OPINION OF THE COURT
GREENBERG, Circuit Judge.
This criminal case comes on before this court on appeals from judgments of conviction and sentence entered June 25, 2001. A jury convicted defendants-appellants Yul Darnell Givan and Wayne Torrence on one count of conspiring to distribute and possess with intent to distribute in excess of 100 grams of heroin in violation of 21 U.S.C. §§ 846, 841(a)(1), and 841(b)(1)(B) and one count of possession with intent to distribute in excess of 100 grams of heroin in violation of 21 U.S.C. §§ 841(a)(1) and 841(b)(1)(B) and 18 U.S.C. § 2.
On appeal, both defendants argue that the district court should have granted their motions to suppress the heroin seized from the vehicle the Pennsylvania state police stopped which Torrence had been driving and in which Givan had been a passenger. They argue in this regard that Torrence did not freely and voluntarily give his consent for the search.
Givan argues that Trooper Jeffrey Taylor violated his Fourth Amendment rights when he continued to question the vehicle’s occupants after the initial reason for the stop had been satisfied. Moreover, he contends that the district court erred when it applied Fed. R. Evid. 404(b) to allow evidence that Givan had been convicted of a felony drug offense in Des Moines County, Iowa, on January 25, 1998. Finally, he contends that the court erred when it allowed Darryl Morgan to testify as to his drug purchases from the defendants as Givan contends that Morgan’s testimony was not relevant to the conspiracy offense charged and was inadmissible under Fed. R.Evid. 404(b).
Torrence contends that his sentence should be vacated because the district court clearly erred in calculating his total offense level in making findings that he was involved in the distribution of between one and three kilograms of heroin and that he possessed a firearm in relation to drug trafficking. Torrence also makes an ineffective assistance of counsel claim, arguing that when deciding to take the case to trial rather than plead guilty, he relied on his counsel’s incorrect calculation of the guideline range that would apply at sentencing after conviction at trial. Finally, Torrence argues that he detrimentally relied upon the government’s statements of what his [456]*456guideline range would be after trial. For the reasons set forth below, we will affirm.
I. BACKGROUND
A. Factual History
On September 8, 1999, at 1:30 p.m., Trooper Taylor pulled over Torrence and his two passengers, John Billings and Gi-van, for speeding on Route 80 in Luzerne County, Pennsylvania, after he clocked their vehicle at 77 miles per hour in a 65 miles per hour zone. In response to Taylor’s request for his driver’s license and registration, Torrence provided a Michigan driver’s license and a rental agreement which indicated that the car had been rented in Michigan less than 24 hours earlier. Taylor asked Torrence to exit the car and accompany him to the patrol car where he showed Torrence the radar reading and wrote Torrence a warning notice for speeding. Taylor then returned Tor-rence’s license and rental agreement and informed him that he was free to leave.
Nevertheless, Taylor then asked Tor-rence if he would mind answering a few questions and Torrence agreed. In response to questions about the destination of his trip, Torrence told Taylor that he had come from New Brunswick, New Jersey, where he visited his sister, who had been in a very bad car accident. By this time a second trooper, Louis Rossi, had arrived to assist Taylor with the stop and Taylor asked Rossi to inquire of Givan and Billings as to from where they had come. Either Givan or Billings told Rossi that they were coming back from New York. Taylor then approached the vehicle, and asked Billings and Givan from where they were coming. Billings, in the front seat, said they were coming from New York. Taylor then asked “Anywere else?” and Givan, in the back seat, leaned forward and said that they came from New York only, where they had been visiting some friends. After hearing the inconsistent explanations describing their travels and observing that Torrence appeared to be nervous, Taylor asked him for his consent to search the vehicle. Torrence said he had nothing to hide and consented to the search whereupon Taylor patted him down.
After obtaining Torrence’s consent to the search, Taylor asked Billings to step from the vehicle. As Billings exited the vehicle, Taylor noticed a tourniquet protruding from his pocket which Taylor then pulled out. Taylor then asked Billings if he was a heroin addict and Billings responded that he had been, but that he was not any more. Taylor asked Billings if he had any needles. Billings responded “yes” and pulled out a needle and put it on top of the vehicle. At that point Taylor observed a white piece of paper protruding from Billings’ front pocket and Taylor pulled the paper out and opened it up. It was a lottery ticket containing a brown powder substance that appeared to be heroin. As Taylor was looking at the substance, Billings grabbed the ticket and threw the substance into the air. The troopers then handcuffed Billings and Torrence. They, however, did not handcuff Givan though they did place him on the ground next to Billings and Torrence.
Rossi and Taylor then searched the vehicle and under its back seat Rossi found a bag of heroin in pellet form. Subsequent laboratory testing revealed that the bag contained 113.5 grams of heroin having a purity level of 43%. The DEA was contacted and Torrence, Givan and Billings were given Miranda warnings and transported to the state police barracks in Ha-zleton, Pennsylvania.
B. Procedural History
After Billings agreed to cooperate in the investigation and entered into a plea [457]*457agreement, a grand jury returned a two-count Second Superseding Indictment against Givan and Torrence on November 30, 1999. Count I charged that on or about and between a date unknown and September 8, 1999, the defendants conspired to distribute and possess with intent to distribute in excess of 100 grams of heroin in violation of 21 U.S.C. §§ 846, 841(a)(1) and 841(b)(1)(B). Count II charged that on or about September 8, 1999, the defendants possessed with intent to distribute in excess of 100 grams of heroin in violation of 21 U.S.C. §§ 841(a)(1), 841(b)(1)(B) and 18 U.S.C. § 2. Both counts added, pursuant to 21 U.S.C. § 851, an allegation of Givan’s prior felony drug conviction. Both defendants pleaded not guilty.
Givan filed a pretrial motion in limine seeking an order precluding the government from offering his prior felony drug conviction into evidence. By Memorandum and Order dated November 13, 2000, the district court denied Givan’s motion. Furthermore, both defendants made unsuccessful pretrial motions to suppress the heroin.
On December 11, 2000, defendants’ joint jury trial began. The government called, among other witnesses, Darryl Morgan. Givan objected to Morgan’s testimony, claiming that it was not relevant to the issue of whether there was a drug conspiracy and that, in any event, it was more prejudicial than probative. The prosecutor informed the court that Morgan would testify that Torrence had introduced Givan to him as someone from whom Morgan could buy drugs, and that Morgan had purchased heroin from Givan during the time period of the conspiracy alleged in the Indictment. The court determined that the evidence was admissible and thus overruled Givan’s objection and allowed the testimony.
On December 13, 2000, the jury convicted Givan and Torrence on both Counts of the Second Superseding Indictment. Tor-rence objected to the subsequently prepared presentence report, arguing that his base offense level should be 26 rather than 32 as proposed in the report, and that, contrary to the proposals in the report, neither a firearms enhancement nor a role enhancement should apply. On June 13, 2001, the district court held a sentencing hearing. At the hearing, Torrence’s counsel notified the court that Torrence had been under the mistaken impression that his likely guideline sentencing range after trial would be 78 to 97 months, in a “worse case situation.” Torrence’s counsel indicated that this mistaken impression was based on a conversation he, the counsel, had had with the prosecutor. The prosecutor confirmed that there had been a discussion .about the possible guideline range in the context of a proposed plea offer but that no formal plea offer had been made. After listening to the arguments, the court overruled Torrence’s objections to the base offense level and the firearms enhancement but upheld his objection to the role enhancement. The court then sentenced Torrence to 151 months imprisonment, to be followed by four years of supervised release, and sentenced Givan to 120 months imprisonment to be followed by eight years of supervised release. Defendants then appealed.
C. Jurisdiction
We have jurisdiction pursuant to 28 U.S.C. § 1291 and 18 U.S.C. § 3742(a). The district court exercised subject matter jurisdiction pursuant to 18 U.S.C. § 3231.
II. DISCUSSION
A. Motion to Suppress
The district court denied Torrence’s motion to suppress as evidence the [458]*458heroin obtained from the vehicle search.1 The court based its decision on its findings that (1) the troopers had probable cause to charge Torrence with speeding; (2) the troopers had a reasonable suspicion to believe that Torrence had committed a crime justifying further investigation; (3) Tor-rence freely and unqualifiedly gave consent to the troopers to search the vehicle. We “review[ ] the district court’s denial of the motion to suppress for ‘clear error as to the underlying facts, but exercise[ ] plenary review as to its legality in light of the court’s properly found facts.’ ” United States v. Riddick, 156 F.3d 505, 509 (3d Cir.1998) (quoting United States v. Inigo, 925 F.2d 641, 656 (3d Cir.1991)).
Neither defendant contests the district court’s first ruling that the initial stop clearly was justified inasmuch as Taylor clocked the vehicle at 77 miles per hour in a 65 miles per hour zone. After a traffic stop that was justified at its inception, an officer who develops a reasonable, articulable suspicion of criminal activity may expand the scope of an inquiry beyond the reason for the stop and detain the vehicle and its occupants for further investigation. See United States v. Johnson, 285 F.3d 744, 749 (8th Cir.2002). While “reasonable suspicion” must be more than an inchoate “hunch,” the Fourth Amendment only requires that police articulate some minimal, objective justification for an investigatory stop. See United States v. Sokolow, 490 U.S. 1, 13, 109 S.Ct. 1581, 1585, 104 L.Ed.2d 1 (1989). In determining whether there was a basis for reasonable suspicion, a court must consider the totality of the circumstances, in light of the officer’s experience. See United States v. Arvizu, 534 U.S. 266, 273, 122 S.Ct. 744, 750-51, 151 L.Ed.2d 740 (2002); United States v. Orsolini, 300 F.3d 724, 728 (6th Cir.2002). Within the last year we have noted that in “the Supreme Court’s most recent pronouncement on the Fourth Amendment reasonable suspicion standard, it accorded great deference to the officer’s knowledge of the nature and the nuances of the type of criminal activity that he had observed in his experience, almost to the point of permitting it to be the focal point of the analysis.” United States v. Nelson, 284 F.3d 472, 482 (3d Cir.2002).
Even assuming, as the district court seemed to do, that the brief questioning following the return of Torrence’s documents occurred while Torrence had been seized for Fourth Amendment purposes rather than during a consensual encounter that began once Torrence’s documents were returned and he was informed that he was free to leave, Taylor had a reasonable and articulable suspicion of illegal activity sufficient to extend the stop the few additional minutes it took to ask the occupants about their travel destinations. Taylor knew at that time that: (a) Torrence had been speeding; (b) Torrence was operating a motor vehicle that had been rented less than 24 hours earlier in Saginaw, Michigan; (c) the estimated driving time from Saginaw to New York City and back to the site of arrest was approximately 17 hours; (d) it is a common practice of drug dealers from other states to make a non-stop trip to New York City [459]*459and back for purchasing drugs; (e) Tor-rence appeared nervous and fidgety and was talking often and shuffling his feet. Furthermore, questions relating to a driver’s travel plans ordinarily fall within the scope of a traffic stop. See United States v. Williams, 271 F.3d 1262, 1267 (10th Cir.2001). After receiving conflicting stories from Torrence and the passengers about their travel, Taylor was justified in further extending the stop and asking for consent to search the vehicle. Thus, the district court did not err in holding that the further investigation was justified.
But the defendants contend that even if Torrence gave his consent to search the vehicle at a time Taylor was justified in extending the stop, Torrence did not give his consent freely and voluntarily. The Fourth Amendment protects the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” Pursuant to the Fourth Amendment, warrantless searches of automobiles frequently are prohibited. It is well settled, however, that a search conducted pursuant to consent is one of the specifically established exceptions to the search warrant requirement. Schneckloth v. Bustamonte, 412 U.S. 218, 219, 93 S.Ct. 2041, 2043-14, 36 L.Ed.2d 854 (1973). In Schneckloth the Supreme Court stated that voluntariness “is a question of fact to be determined from the totality of all of the circumstances.” Id. at 227, 93 S.Ct. at 2048. The district court’s determination that Torrence’s consent was voluntary was a determination of fact subject to review on a clear error basis. See United States v. Kelly, 708 F.2d 121, 126 (3d Cir.1983).
In United States ex rel. Harris v. Hendricks, 423 F.2d 1096 (3d Cir.1970), we elucidated the critical factors comprising a totality of the circumstances inquiry as including the setting in which the consent was obtained, the parties’ verbal and nonverbal actions, and the age, intelligence, and educational background of the consenting individual. See id. at 1099. When we apply the totality of the circumstances test to the facts adduced at the suppression hearing, we conclude that the district court’s determination that Torrence voluntarily gave his consent rather than did so by reason of duress or coercion, cannot be said to be clearly erroneous.
The facts in the record supporting the district court’s determination include: (1) Taylor returned Torrence’s license and advised Torrence that he was free to leave before asking Torrence if he would mind answering a few questions and Torrence said that he did not mind; (2) after asking Torrence some initial questions Taylor asked Torrence if he would mind if Taylor looked in the vehicle and Torrence replied that he had nothing to hide and Taylor could go ahead and look; (3) Taylor testified that when he asked Torrence for his consent, he told Torrence that his consent had to be voluntary and that Torrence did not have to allow the search; (4) both troopers testified that Torrence gave consent without any coercion or duress and this testimony was unrebutted; (5) Tor-rence gave his consent while standing on the side of a major highway in broad daylight, see United States v. Velasquez, 885 F.2d 1076, 1082 (3d Cir.1989), and prior to being handcuffed. There is nothing in the record indicating that Torrence’s age, intelligence or educational background in any way limited his ability to consent voluntarily to the search. Torrence cites the decision of the Court of Appeals for the Sixth Circuit in United States v. Mesa, 62 F.3d 159 (6th Cir.1995), in support of his position that the district court erred in denying his motion to suppress. But, as the government points out, Mesa is inap-posite because its facts materially differ [460]*460from those here. Most notably, Mesa was locked in the back of a police vehicle when she consented to a search of the vehicle. See id. at 161. The totality of the circumstances in this case are more similar to those in United States v. Velasquez, 885 F.2d at 1081-82, and indicate that Tor-rence freely and voluntarily consented to the search. The district court’s finding of voluntariness was not clearly erroneous.
B. Evidence of Givan’s Prior Felony Drug Conviction
We next discuss Givan’s argument that the district court erred when it admitted into evidence under Fed.R.Evid. Rule 404(b) testimony to the effect that Givan had been convicted of a felony drug offense in Des Moines County, Iowa, on January 25, 1993. To the extent that our review of this ruling requires us to consider the district court’s interpretation of the rules of evidence our review is plenary. See United States v. Furst, 886 F.2d 558, 571 (3d Cir.1989). But, assuming that the evidence could be admissible in some circumstances, we review the district court’s decision to admit it on an abuse of discretion basis. See United States v. Console, 13 F.3d 641, 658-59 (3d Cir.1993); United States v. Saada, 212 F.3d 210, 223 (3d Cir.2000).
Fed.R.Evid. 404(b) provides in relevant part that: “Evidence of other crimes, wrongs or acts is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity or absence of mistake or accident. ...” We have recognized that Rule 404(b) is a rule of inclusion rather than exclusion. See United States v. Jemal, 26 F.3d 1267, 1272 (3d Cir.1994). We favor the admission of evidence of other criminal conduct if such evidence is “relevant for any other purpose than to show a mere propensity or disposition on the part of the defendant to commit the crime.” United States v. Long, 574 F.2d 761, 765 (3d Cir.1978) (quoting United States v. Stirone, 262 F.2d 571, 576 (3d Cir.1958), rev’d on other grounds, 361 U.S. 212, 80 S.Ct. 270, 4 L.Ed.2d 252 (1960)). In Huddleston v. United States, 485 U.S. 681, 108 S.Ct. 1496, 99 L.Ed.2d 771 (1988), the Supreme Court set out a four-part test for admission of Rule 404(b) evidence: (1) the evidence must have a proper purpose; (2) it must be relevant; (3) its probative value must outweigh its potential for unfair prejudice; and (4) the court must charge the jury to consider the evidence only for the limited purposes for which it is admitted. Id. at 691-92, 108 S.Ct. at 1502; United States v. Vega, 285 F.3d 256, 261 (3d Cir.2002).
The government argues that Givan’s 1993 conviction was proper Rule 404(b) evidence because it was probative of Gi-van’s intent, knowledge, and absence of mistake or accident. The government argues that because it had to prove that Givan knew, prior to its discovery by the troopers, that a quantity of heroin was hidden in the back seat of the rental car and that it had to prove that Givan possessed the heroin with intent to distribute it, “knowledge and intent were material and contested issues at trial.” Br. of Ap-pellee at 47. The government also argues that the evidence was offered to rebut a defense of innocent association. The district court accepted the government’s argument stating that the “circumstances of this case illustrate the probative value of Givan’s past drug conviction on the question of whether he had knowledge of the heroin in the back seat; whether, with such knowledge, he had intent to secret it; and that the presence of heroin immediate[461]*461ly underneath his body was not there because of accident or mistake.” Givan’s app. at 30.
Knowledge, intent, and lack of mistake or accident are well-established non-propensity purposes for admitting evidence of prior crimes or acts. See Fed.R.Evid. 404(b). Inasmuch as a showing of knowledge, intent and lack of mistake or accident was essential for the government to meet its burden of proof in this case, and the 1993 felony drug conviction was evidence that the jury could consider as shedding light on the key issues of whether Givan knew about the drugs in the vehicle, the court admitted the prior felony conviction for a proper purpose. See United States v. Parsee, 178 F.3d 374, 379 (5th Cir.1999); United States v. Martino, 759 F.2d 998, 1004-05 (2d Cir.1985).
In the circumstances, taking into account our holding with respect to Rule 404(b), we conclude that the evidence of Givan’s felony conviction passes the less focused admissibility threshold in Fed. R.Evid. 401. Under Rule 401 relevant evidence means “evidence having a tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence.” The evidence that Givan had been convicted of distribution of cocaine makes Givan’s knowledge of the presence of the heroin more probable than it would have been without the evidence as it indicates that Givan had knowledge of drugs and drug distribution, and thus that it was less likely that he was simply in the wrong place at the wrong time. Therefore, being relevant the evidence of the prior conviction was not inadmissible as a matter of law. See Fed.R.Evid. 402.
Even though we have concluded that evidence of Givan’s 1993 felony drug conviction was not inadmissible on a legal basis, we must evaluate the evidence against the unfair prejudice standard of Fed.R.Evid. 403. See Government of Virgin Islands v. Harris, 938 F.2d 401, 420 (3d Cir.1991). Fed.R.Evid. 403 provides that relevant evidence may be excluded if, inter alia, “its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury....” We review the district court’s application of Rule 403 on an abuse of discretion basis. See id. But as we stated in United States v. Long, 574 F.2d at 767, “[i]f judicial self-restraint is ever desirable, it is when a Rule 403 analysis of a trial court is reviewed by an appellate tribunal.”
Givan argues that the district court failed to engage in a Rule 403 balancing of the probative value versus the prejudicial effect of admitting his prior felony drug conviction and that this omission requires us to reverse his conviction. However, in its Memorandum and Order denying Gi-van’s motion in limine requesting the court to preclude the government from offering into evidence Givan’s 1993 felony drug conviction the district court found that “the probative value of the prior conviction is not substantially outweighed by the danger of unfair prejudice to the defendant.” Givan’s app. at 30. While the district court did not set forth its reasons for concluding that the scale tipped in favor of admission of the evidence, the court did provide the jury with a limiting instruction regarding the prior conviction in which the district court emphasized the limited purpose for which the evidence was admissible,2 thereby minimizing any preju[462]*462dicial effect. Givan does not claim that the district court’s limiting instruction was inadequate to prevent unfair prejudice. Overall, we cannot find that the district court abused its discretion under Rule 403.
In upholding the admission of the Rule 404(b) evidence, we recognize that Judge McKee in his dissent contends that “the jury could only have considered the prior conviction to establish Givan’s criminal propensity,” dissent at 26, and makes much of the circumstance that the prior conviction involved cocaine and not heroin as here. We note, however, that it is a basic tenet of our jurisprudence that a jury is presumed to have followed the instructions the court gave it, see United States v. Gilsenan, 949 F.2d 90, 96 (3d Cir.1991), and the court’s instructions did not allow the use of the evidence in the way that Judge McKee contends that it used it. If we preclude the use of evidence admissible under Rule 404(b) because of a concern that jurors will not be able to follow the court’s instructions regarding its use we will inevitably severely limit the scope of evidence permitted by that important rule. Moreover, the distinction Judge McKee draws between the types of drugs involved is of limited significance in the context of this case in which the conviction is germane only with respect to Givan’s knowledge of the presence of drugs. It is not as if dealing in cocaine and heroin are mutually exclusive endeavors. Finally on this point we note that our result is consistent with that reached by other courts of appeals. See, e.g., Parsee, 178 F.3d at 379; Martino, 759 F.2d at 1004-05. These cases cannot be distinguished reasonably from this case so that if we reject the Rule 404(b) evidence we will create a conflict among the circuits.
C. Morgan’s Testimony
Givan also argues that the district court erred when it allowed the jury to hear the testimony of Darryl Morgan because his testimony constituted evidence of other criminal conduct impermissible under Fed.R.Evid. 404(b), or, alternatively, Morgan’s testimony was not relevant to the conspiracy count of the indictment. The government argues that Morgan’s testimony was directly relevant to the existence of a drug conspiracy involving Tor-[463]*463rence and Givan and that Morgan’s testimony was proof of the existence of the drug conspiracy charged in Count I of the Second Superseding Indictment. We review the district court’s decision to admit this evidence on an abuse of discretion basis. See United States v. Sokolow, 91 F.3d 396, 402 (3d Cir.1996).
The government is correct that Morgan’s testimony was relevant because it made the existence of a key fact — 'that Torrence and Givan were working together in a conspiracy to distribute heroin in and around Saginaw, Michigan, during 1999 — more probable than it would have been without his testimony. Morgan testified that he was aware of a drug conspiracy in Saginaw involving Torrence and Givan. In particular, he testified that Torrence had introduced Givan to him as someone from whom he could buy drugs and that he bought heroin from either Torrence or Givan on a daily basis from March to September 1999. Moreover, he testified that Torrence and Givan had split up the Saginaw area, with Torrence selling on the west side of town, and Gi-van on the south side and because he lived closer to the south side, it was often more convenient for him to buy from Gi-van. He also testified that if he paged Torrence and Torrence was not available, he would page Givan.
In the circumstances Morgan’s testimony was direct proof of existence of the drug conspiracy alleged in the indictment and was not subject to the limitation in Rule 404(b) of the admissibility of evidence of “other crimes, wrongs, or acts.” See United States v. Maynie, 257 F.3d 908, 915 (8th Cir.2001); United States v. Sriyuth, 98 F.3d 739, 747 (3d Cir.1996); United States v. Retos, 25 F.3d 1220, 1228, n. 10 (3d Cir.1994); 22 C. Wright & K. Graham, Federal Practice and Procedure § 5239, at 450 (1978). Thus, the district court did not abuse its discretion in allowing the jury to hear Morgan’s testimony.
D. Base Offense Level and Firearms Enhancement
Torrence contends that the district court clearly erred in finding that he was involved in the distribution of between one and three kilograms of heroin and that he possessed a firearm in relation to drug trafficking. We review the district court’s findings of fact on these issues for clear error, see United States v. Miele, 989 F.2d 659, 663 (3d Cir.1993), but apply plenary review to its construction of the Sentencing Guidelines, see United States v. Bethancourt, 65 F.3d 1074, 1080 (3d Cir.1995). When sentencing a defendant, the district court only need base its determinations on the preponderance of the evidence with which it is presented. See United States v. McDowell, 888 F.2d 285, 291 (3d Cir.1989). Information used as a basis for sentencing must have “sufficient indicia of reliability to support its probable accuracy.” U.S.S.G. § 6A1.3(a).
The testimony established by a preponderance of evidence that Torrence was involved in the distribution of at least one kilogram of heroin. Billings testified that during the years of 1995, 1996, and 1997 he and Torrence traveled to Chicago approximately every three months to purchase $15,000-$30,000 worth of heroin and cocaine and that in 1998 and 1999 he and Torrence traveled to New York approximately every three months to obtain $30,000 worth of heroin and/or cocaine. Billings testified that $30,000 would buy eight to nine ounces of heroin in New York. According to Billings, Torrence made at least five trips for heroin, each time for eight ounces, for a total of 40 ounces, or one and three tenths kilograms. Billings’ testimony was also consistent with the quantity of drugs found in the car. [464]*464Billings testified that he and Torrence bought two packages of heroin that day but that he did not know what happened to one of the packages. The fact that one package was seized from the vehicle, weighing almost four ounces, supported Billings’ testimony that they bought eight ounces that day for $30,000.
The heart of Torrence’s argument is that the district court erred in relying on Billings’ testimony because of his unreliability. While Billings is a drug addict, his testimony, in contrast to that considered in United States v. Miele, 989 F.2d at 667, was not internally inconsistent and, also in contrast to that in Miele, was corroborated by the testimony of another witness, Darryl Morgan. See id. at 664-65. Billings’ and Morgan’s testimony was subject to vigorous cross-examination and at the sentencing hearing the district court listened to extensive argument on the issue of drug quantity. The court, which observed their demeanor and was in a position to judge their credibility, carefully considered the estimates based on their testimony and concluded that the witnesses were reliable. As we have stated “assessments of credibility by the trial court are entitled to great deference at the appellate level.” United States v. Brothers, 75 F.3d 845, 853 (3d Cir.1996). Because we agree that there was at least a minimal indicia of reliability to support the court’s reliance on Billings’ and Morgan’s testimony relating to drug quantity, we conclude that its drug quantity calculation was not clearly erroneous.
Torrence also argues that the district court clearly erred in finding that he possessed a firearm in relation to drug trafficking. The court took Torrence’s possession of a firearm into account in adding two points to his offense level, in accordance with U.S.S.G. § 2Dl.l(b)(l).
The government established by a preponderance of evidence that a firearm was used at the time the offense was committed. Billings testified that Torrence gave him a gun to protect them on every trip they took to pick up drugs and that in particular Torrence gave him a gun on the September 7, 1999 trip. This testimony was subject to cross-examination and was not rebutted. The district court, after listening to arguments from Torrence’s counsel and the government, and then relying on its own recollection of the evidence, concluded that Billings was credible on this point and that the firearms enhancement should apply. While Torrence makes much of the fact that the troopers did not recover the firearm from the vehicle or at the scene of arrest, there is no support for his argument that such recovery is a prerequisite to the application of the firearms enhancement. Similarly, there is no support for his argument that he should not have received the firearms enhancement because Billings did not receive it. The district court’s determination that the firearms enhancement should apply was not clearly erroneous.
E. Ineffective Assistance of Counsel and Due Process
Torrence also claims that his right to effective assistance of counsel was violated because in deciding to take the case to trial rather than plead guilty, he relied upon his counsel’s incorrect calculations of the guideline range that would apply at sentencing after a conviction at trial. However, claims of ineffective assistance of counsel ordinarily are not cognizable on direct appeal. United States v. Mustafa, 238 F.3d 485, 497 (3d Cir.2001); United States v. Tobin, 155 F.3d 636, 643 (3d Cir.1998). Rather, the proper mechanism for challenging the efficacy of counsel is through a motion pursuant to 28 U.S.C. § 2255. As the government points out, [465]*465the record in this case is inadequate for us to address the issue of ineffective assistance of counsel for, even if we accept as true all of Torrence’s factual assertions, the record does not establish what, if any, prejudice Torrence suffered by reason of the incorrect calculation of his anticipated guideline range. For example, for all we know Torrence might have gone to trial regardless of the calculations supplied. See United States v. Sandini, 888 F.2d 300, 312 (3d Cir.1989) (“[C]laims predicated upon attorney’s error do require a showing of prejudice and therefore may involve facts not adequately developed in the record.”) (emphasis in original).
Torrence’s last argument is that he detrimentally relied upon the government’s erroneous statements during plea discussions before trial of what the applicable guideline range would be. Citing Santobello v. New York, 404 U.S. 257, 92 S.Ct. 495, 30 L.Ed.2d 427 (1971), and Virgin Islands v. Scotland, 614 F.2d 360 (3d Cir.1980), he contends that the government should have been estopped based on these statements from asserting that his base offense level was higher than 26 and that we should vacate his sentence and require the trial court to accept as binding a base offense level of 26. The record indicates that the parties’ counsel had a pretrial discussion concerning the applicable guideline range, and that they underestimated the base offense level that would apply after trial. However, in contrast to the situation in Santobello and Scotland, the government never made any formal plea offer to Torrence. In these circumstances there is no support for Torrence’s argument that the government should have been estopped from asserting that he was subject to a base offense level higher than 26.
III. CONCLUSION
For the foregoing reasons, we will affirm the judgments of convictions and sentence entered June 25, 2001.