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Toyota Tundra vs. Chevrolet Silverado



  • beliasbelias Posts: 316
    I think there is a little misunderstanding here. Let me clarify. Marketing typically gathers information about what the market actually wants to see in a vehicle. They also collect information on test groups in terms of their reactions to certain designs, features, etc. When they have a particular "package" in place, they bring it to management and engineering. In essence, they produce a requirements document. Engineering can fulfill those requirements in literally dozens of different ways. Yes, upper management obviously has the final say in budgeting, but marketing also determines what prices customers are willing to accept and the kind of tolerance they have for it (price sensitivity). There are actuaries that make calculations based on different pricing models.
    Ultimately a particular package comes together. The reason why 99% of the concept vehicles are scaled down so much in production (if any of them actually make it that far) has less to do with engineering than it does with marketing and upper management. I was just trying to clarify that engineering certainly has little to say about the final outcome... they're producing to meet a set of requirements, not producing "freely" and trying to fit that into the market. There are instances where they bring many different innovations, but ultimately it is other groups that help determine the final outcome.
  • beliasbelias Posts: 316
    pmusce, yes GM has done much better with gap tolerances, but Toyota's situation is completely different. First off, there is hardly a company that is better at this then they are; they've proved it handily on a number of their vehicles. Secondly, they themselves stated that gap tolerances were higher because in their research it amounted to the perceived notion of being tougher. Third, unlike other manufacturers, they made the assertion themselves; this was not discovered by somebody that had a bone to pick. Other manufacturers simply could not do it as well as Toyota. They are getting much better though. So, it isn't as if this is Toyota not capable of making very tight gaps... it is simply a decision they made based on their research.
  • pmuscepmusce Posts: 132

    I agree with this explanation completely. This was not what you originaly posted or implied with respect to why GM used a fully boxed frame.
  • pmuscepmusce Posts: 132
    If you actually believe that they have larger tolerancs because marketing research says its percieved to be tougher, you go ahead and believe that. Do you think it makes the a truck look tough to have large tolerances? I think tighter tolerances look better on all vehicles, but then again I was not part of Toyota's 'market research'.
  • beliasbelias Posts: 316
    I'm not saying that I believe the truck actually "looks" tougher. I'm saying that Toyota came out and said that as an explanation -- we may not even be broaching the subject if they didn't mention it. Personally, I like tight gap tolerances. I have no idea if it would look as tough or not without them. But that is the explanation Toyota gave.
  • beliasbelias Posts: 316
    Did you mean what kdhspyder wrote about that? I only commented on how design is determined... I don't recall specifically talking about how GM came to do a FBF.
  • kdhspyderkdhspyder Posts: 7,160
    Marketing is NOT beancounters at all. Marketing is the 'artistic' sales-oriented part of the business.
    Marketing includes
    ..those who do comparo's between the vehicles ( like here );
    ..those that look at the pricing differences to make sure one is not too high ( lost sales ) or too low ( lost profit );
    ..those who go out into the public and ask questions about what the user wants in a vehicle;
    ..those that do demographic studies about where trucks are sold, what kind of hobbies the owners have, how much is spent on accessories, what the trade-ins are, etc
    ..those that look up governmental regulations, CAFE, towing, taxes, etc

    Marketing puts all this together and makes a presentation to the Marketing Management with a profile ( or multiple profiles ) of what a truck owner is like. Then they make a presentation about what the competition is like; i.e. all the competitors advantages and disadvantages. Then they make an estimate about what volume could be sold and from which competitor they will take volume. Then they make a recommendation about what the new vehicle should be like. Normally they want a vehicle that has everything in it and no increase in price.

    If they can get this vehicle they will 'eat the competition alive'.

    Marketing Management tones down this because they know when they present this proposal for the 2012 Silvy or Tundra to Top Management that Accounting ( beancounters ) or Engineering will either laugh at them or simply say 'NO, this cannot be done'.

    It is marketing that 'creates' the next vehicle at least as a concept. Once the new vehicle is agreed upon then the general 'concept' is given to the designers and engineers to actually do it.
  • kdhspyderkdhspyder Posts: 7,160
    This is the key phrase from my post....Finally a compromise is reached.

    You misunderstand the term Marketing I think. Engineering doesn't care one way or the other because they aren't charged with selling the vehicles. Marketing is. I am certain that the impetus for putting in this stronger frame came from Marketing because they didn't want the new T900 to look bad vis-a-vis the F150.

    Again I ask where do you think the idea came from? And then why suddenly in 2006, not earlier?
  • pmuscepmusce Posts: 132
    I think we just disagree as to how much influence marketing has on product decisions. Lets just leave it at that. As to why not earlier than 2006?. Well the last new pickup (GTM800) came out in the 1999 model year, the one before that (C/K) in 1988. Again, there is no use arguing about the benefits of a fully boxed frame because you are convinced its not a benefit just because Toyota does not have it on the Tundra. When the next Tundra has it, we won't have anything to discuss. It will be interesting to see if the HD Tundra's have a fully boxed frame when they come out.
  • rorrrorr Posts: 3,630
    "Again, there is no use arguing about the benefits of a fully boxed frame because you are convinced its not a benefit just because Toyota does not have it on the Tundra."

    I don't want to answer for kdhspyder but.....

    Frame strength is dependent on a large set of variables:

    Grade of steel
    Thickness of steel
    Ratio of dimensions of the member (height x width)
    Number/type of welds
    Number/type/dimensions of cross pieces
    Number and placement of either lightening holes or mounting holes
    Method used to form the steel members
    etc. etc. etc.

    The pro-GM faction is locking on to a SINGLE variable (full box section vs. C-channel) and (apparently) ASSUMING that every single other variable is either unimportant or identical between the vehicles.

    Is there any real DATA that indicates the GM frame is stronger? Stronger is what areas (torsion? bending?).

    Hey guys, a SOLID steel member would be even stronger than a fully boxed section. How come we don't see solid steel sections? Answer: because solid sections are unnessary to achieve the required design strength and would impose unnessary penalties with regards to weight and cost. Engineering is used to determine the best method of achieving design parameters at the lowest weight/cost.

    And if Toyota's engineers were able to achieve their design parameters using open C-sections in some locations (and fully-boxed sections in others), are any of you actually QUALIFIED to say otherwise?


    Something else to consider - conventional wisdom says a 6.0l motor is stronger (in both hp and torque) than a 5.7l motor. And, IF ALL ELSE WAS EQUAL, such would be the case. Yet I think it's pretty clear that the 5.7l motor in the Tundra is NOT weaker than the 6.0 in the Silverado. So why the assumption that the fully boxed section frame on the Silverado is stronger than the frame on the Tundra?
  • blkhemiblkhemi Posts: 1,717
    Dr.Fill, I knew you were sub-human, maybe from a different planet.

    We go way back, and you know that I respect you as a poster. But let's check the accolades list since you decided to go there.

    The top publications have all endorsed the Silverado with their top awards. The Tundra has won some notable, but albeit minor, awards in comparison.

    As to the boxed/closed section frame, a fully-boxed-frame adds structural intergrity to the truck. I guess none of you have ever built house and used a closed-section flooring and roofing. It's like a cloth top covertible car, without the roof on, the structure will shake to some degree. The vibrations and shakes associated with Ford and some 4WD-equipped Rams has nothing to do with the frames. Dodge knows it's the driveshafts in the Rams, and Ford now says it's the transmission that gives offs resonances with the F-150.

    And as to the Ram, again, why pick on the oldest design in the segment to prove a point? Yes the towing is lacking compared with 6 m/y newer trucks. The '06 Toyota Tundra is out-towed by an '07 Dodge Dakota for comparison.

    And on panel gaps? They're getting wider by the minute at Toyota. Oh sure, it lets more air in. It looks more dated than a '79 Oldmobile. And it adds ruggedness!!! Please take that baloney somewhere else to folks that are listening.
  • maple2maple2 Posts: 177
    The pro-GM faction is locking on to a SINGLE variable (full box section vs. C-channel) and (apparently) ASSUMING that every single other variable is either unimportant or identical between the vehicles.

    Is there any real DATA that indicates the GM frame is stronger? Stronger is what areas (torsion? bending?).

    While I think this is really a non issue as I dont expect either truck to have any frame issues, but if you really want to start splitting hairs over it, I think the fact that toyota acknowledges that f-b-f must be stronger otherwise why would they include it in the areas of the frame that see the most twisting and torsional loads? If the open "c" frame was superior, or even equal for that matter, than why not use it all the way back to front?
  • titancrewtitancrew Posts: 14
    Since no one has really answer the question why a Fully-Boxed-Frame (FBF) is better than an open channel (C-channel Frame), I’ll give it try. Or at least explain the advantages and disadvantage of C-channel frames and FBF. Since I don’t know the dimensions of the Tundra’s frame or the Silverado/Sierra’s frame, I’ll use standard AISC (American Institute of Steel Construction) shapes as examples. So…is a FBF stronger than a C-channel? Bending and torsional strength or stiffness are usually the two criteria that manufacturers like mention when comparing a new vehicle’s frame or body structure to its predecessor. Let’s examine bending or vertical loads. Common sense tells us that a FBF should be stiffer than a C-channel frame given that they both have the same depth or height, width, and thickness. But let’s examine the numbers to see if it is stiffer and by how much. For example, let’s compare a C6x10.5 C-channel to an HSS6x2x5/16 rectangular section (Both can be found in the AISC Manual of Steel Construction). I chose theses two because they are similar with regards to external dimensions. A C6x10.5 section has a depth of 6.0 inches, a width of 2.03 inches, web thickness of 0.314 inch, flange thickness of 0.343 inch (the flange is actually at a slope but it’ll suffice for this discussion), and weighs 10.5 lbs/ft. An HSS6x2x5/16 has a depth of 6.0 inches, a width of 2.0 inches, a wall thickness of 0.291 or ~5/16 inch, and weighs 14.8 lbs/ft. These are published NOMINAL dimensions by the way. The section property that measures how stiff a section is in bending is its Area Moment of Inertia (not to be confused with Mass Moment of Inertia for all you ME’s out there) normally represented by an “I”. The bigger the “I”, the more load it can carry before being overstressed. The Moment of Inertia for a C6x10.5 is 15.1 in^4. The Moment of Inertia for an HSS6x2x5/16 is 15.3 in^4. Therefore the rectangular section is stiffer than the C-channel, but by only 1%. But the rectangular section weighs almost 41% more than the C-channel. Hmm…let’s add 41% more steel to increase the bending stiffness by 1%. Brilliant!! Confused? That’s because the “extra” material is added in the wrong location to be effective for bending resistance. The extra material needs to be added as far away from the centroid as possible. That's where Toyota reinforced the frame rail on under the cab, at the top and bottom flanges. And all Mechanical and Civil Engineers (ME and CE) know, or should know that the deeper the section, the stiffer it is in bending, in general. So what if we picked a C-channeled that weighed about the same as this HSS section, a C8x13.75 for example (weight = 13.75 lbs/ft). It has a moment of inertia of 36.1 in^4. That’s 235.9% increase in bending stiffness compared to the HSS6x2x5/16. Now that’s brilliant!! Well, some will argue that the deep C and I sections are susceptible to web buckling. Not if the web is braced in the horizontal direction at certain intervals (e.g. cross members). Ever wondered why all the commercial trucks (box vans, semi-tractors, etc.) have deep C-channel frames? Ford and GM HD pickups (I don’t know about Dodge) still uses C-channel frames. Is it because they’re more efficient for weight carrying. So what’s so about torsional stiffness then? Common sense tells us or tells me that a square or rectangular section is stiffer than an open C-channel. In fact, that’s where the boxed or rectangular section has the C-channel beat by a mile. The HSS6x2x5/16 has a Torsional Stiffness Constant, “J” of 7.60 in^4. The C6x10.5 has a Torsional Stiffness Constant of only 0.128 in^4. That’s almost 6000% greater! That’s why a convertible is not as stiff as a coupe. And a round tube or circular section has the best torsional stiffness to weight ratio. That’s why drive shafts or anything that has to transmit torque is round. But the ME’s will also tell us that the torsional stiffness of a frame is not solely governed by the torsional stiffness of the two main rails and that the cross members contribute to the overall torsional stiffness of the frame. For example, when the frame is twisting (such as when the left-front and right-rear wheels are up and the right-front and left-rear wheels are down or vice-versa), the there’s probably a good deal of bending in the cross members and some twisting of the frame rails. They are being bent. What’s does this have to do with the new Tundra and new GM pickups? Well, I was looking at the new Tundra at the locale dealer that also sells Chevys and noticed that the frame rails of the Silverado at the rear wheels were shorter than the Tundra. I didn’t check out the size of the frame rails at the cab on both vehicles though. But I noticed that the frame rails of the Silverado HD pickups were deep C-channels at the rear wheels. I guess GM didn’t let their “real” truck engineers design the new ½ ton pickups. So, yeah…a boxed section is more costly…duh! It has more steel! Anyways, boxed frame is nothing new. Check out a pre-tacoma Toyota pickup. It has a FBF. Then Toyota went with a C-channel on the Tacoma. Alright, class dismiss and there will be a quiz on all of this next week. :-)
    Sorry for the long post, but hope it helps.
  • 1offroader1offroader Posts: 208

    Although I didn't check the specs on your examples, your engineering analysis is correct. However, since we don't know the dimensions of either frame it's speculation, albeit educated speculation, at this point.

    First off, let me explain a little about my background and qualifications. I’m not an automotive engineer, but in my college days at UCLA in the 70s I took an upper division engineering course called Engineering 108 – Mechanics of Deformable Solids. The course taught about bending moments, torsional and linear stresses, etc. Basically, the course provided a working knowledge of how engineered materials behave under stress. It was heavy on calculus and physics, and was damn difficult. But I learned a lot.


    In terms of stiffness, once the design load can be safely carried the frame doesn't need to be any stiffer. The C-channel and boxed frame are about equal, unless one is much larger dimensionally than the other. For the record, a fully boxed frame is FAR superior in terms of torsional rigidity. That’s why trailer hitches are built of square (or round) tubing, not C-channel. Fully boxed frames are also more expensive, as titancrew stated.

    I haven't looked under the Tundra, but the cross members on the Silverado go through both sides of the boxed frame, and they are welded. The cross members transfer the stress to both of the frame rails. When the opposite corners of the vehicle are lifted, as happens often when offroading, the boxed frame is able to take the torque with much less flex.

    My old 69 Bronco, 85 Toyota 4x4, 92 Toyota 4x4, and 99 Trooper all had fully boxed frames. These vehicles were designed to go offroad. And now my 07 Silverado does, too. Boxed frames are nothing new, but they are effective. The reason large trucks don't use a boxed frame is because they are used for load hauling, not offroading. The C-channel is more efficient, cost and weight-wise, than the boxed frame for purely load carrying. The boxed frame is WAAAAY better if you are going off road where one or more corners of the vehicle may be unsupported. When was the last time you saw a Peterbuilt off road?

    That said, anyone who would load the Tundra (or Silverado) to the point of frame failure is an idiot. The strength difference is WAY out on the stress/strain curve where no one operates a mechanical device, except idiots. The practical difference is nil, just like the practical difference in sub-second ¼ mile performance, or a few extra pounds of rated towing capacity at the ragged edge of safety.

    I think Toyota chose to use the cheaper C-channel frame because it set the price point of the Tundra near the competition. It used an expensive engine and transmission, which gobbled up a lot of the sales price. In addition, Toyota needs to recoup the cost of the new plant in Texas. Therefore, it had to compromise in other areas – items mentioned numerous times before such as no rear locker, no OnStar, cheaper interior. And a cheaper frame.

    To my knowledge, neither the Laws of Physics nor the Laws of Economics have been repealed (although the California Legislature is trying to do the latter). The Laws of Economics dictate that the Tundra cannot offer everything ‘standard’ and still compete at the price point it set for itself. Toyota wants to sell enough Tundras to gain a foothold in the full-size market. And, knowing Toyota, they have a decent chance of doing that.

    The larger body gaps may also be a result of the frame design - Toyota knows that with the add'l. frame flex it has to have more tolerance between body parts so they do not rub against each other. A "rugged look" is BS. It's an engineering necessity caused by the decision to use the open frame design.

    I’ll go out on a limb here and predict the next gen Tundra will offer a rear locker (perhaps optional), a boxed frame, better interior, and some sort of safety system such as the OnStar. And a higher price.

    Anyone care to take that bet?

  • beliasbelias Posts: 316
    And as to the Ram, again, why pick on the oldest design in the segment to prove a point? Yes the towing is lacking compared with 6 m/y newer trucks. The '06 Toyota Tundra is out-towed by an '07 Dodge Dakota for comparison.

    And on panel gaps? They're getting wider by the minute at Toyota. Oh sure, it lets more air in. It looks more dated than a '79 Oldmobile. And it adds ruggedness!!! Please take that baloney somewhere else to folks that are listening.

    First, it is nobody's fault but Dodge's if they have an old design. They have an 07 truck just like everybody else here. When they come out with a new design in 09 you can bet they are going to compare to the other 09s which will be 3 year old designs too.

    Panel gaps getting wider by the minute? They're still a lot tighter than most trucks out right now... just go and look. Again, this is something that Toyota talked about.

    Letting more air in? Perhaps you have never been in a truck before... see air gets in through the engine at several places such as through the front and underneath where it is OPEN. No air gets in the cab on any truck because they seal those gaps... otherwise we would be leaking water like the midgates on Avalanches. So, if anything, the only thing that panel gaps risk are perhaps more wind noise. But that hasn't been an issue on any truck in reviews.

    Also, nobody said that it adds ruggedness... again get a grip and read what was written. Toyota claimed that they felt that it LOOKED more rugged. Nobody on this board said that it added ruggedness or that they even liked the panel gaps. But chances are if there are people that expressed it, they would be from around Texas because a lot of the market research for this truck came from there. In any case, Toyota has more than proved themselves in this area unlike other manufacturers that have yet to get there. It would be like me making the argument against Chevy not knowing how to make a 6.2l engine. GM uses them already in Caddys and GMC, so they've proved it already... just because Chevy doesn't use it in their truck doesn't mean they don't know how.
  • drfilldrfill Posts: 2,484
    Full-size truck buyers aren't used to tight panel gaps. They expect wider gaps.

    Toyota wants to gain acceptance, not change buyers habits. Lexus-level gaps not required.


    Since the Tundra was a mid-year addition, you know it wasn't eligible for most of those awards. So throwing awards up in my face doesn't mean anything.

    As you well know, Lexus can't count how many awards they've won here for their vehicles, many fold more than Audi, which has to go abroad for love.

    Are you saying Lexus vehicles are better than Audi? I knew you had the love! Why fight it? Bask in the afterglow. :D

    So you're saying the excuse for drivability so bad, it shakes the vehicle every time it moves is bad trannys and driveshafts, after 3-4 years on the market, and mid-gen updates. That makes me feel so much better! :)

    Come get your fully-boxed frame here......crappy performance and poor quality thrown in at no extra charge.....0%? $3k off? $5k off?

  • pmuscepmusce Posts: 132
    I do realize there are many variables that make up how strong a frame is. The GMT800's has open C-sections like the Tundra. Their new frame is stronger than the GMT800 frame.

    Conventional wisdom would say that a 6.0L motor is stronger than a 5.7L if both motors are Overhead Cam or Overhead Valve. In this case one is Overhead Cam and one is Overhead Valve. Do you realize that the Tundra 5.7 is physically larger than the GM 6.0? In fact, the 4.8, 5.3 and 6.0L GM V8 engines are all physically the same size. They share the same block.

    By the way I checked both and to get maximum payload and towing capacities for different configurations. I'll include the Heavy Duty Silverado 2500 just for information purposes. GM also has a Heavy Duty 3500 Silverado with even higher capacities. The results are interesting and I don't see the Tundra having this huge advantage like most on this board think:

    Payload 2WD Standard Bed
    Tundra - 1750
    Silverado - 2160
    (Silverado HD - 3604)

    Payload 2WD Long Bed
    Tundra - 2065
    Silverado - 1812
    (Silverado HD - 3892)

    Payload 4x4 Standard Bed
    Tundra - 1680
    Silverado - 2013
    (Silverado HD - 3353)

    Payload 4x4 Long Bed
    Tundra - 2000
    Silverado - 1850
    (Silverado HD - 3646)

    Towing V6 2WD
    Tundra - 5100
    Silverado - 5300
    (Silverado HD - Not available with V6)

    Towing V6 4x4
    Tundra - 4x4 not available with V6
    Silverado - 5100
    (Silverado HD - Not available with V6)

    The next part is tougher because Toyota has one mid level V8 and GM has 2 so I included both:

    Towing Mid Level V8 2WD
    Tundra 4.7 - 8500
    Silverado 4.8 - 7200
    Silverado 5.3 - 8200
    (Silverado HD - Not available with mid level V8)

    Towing Mid Level V8 4x4
    Tundra 4.7 - 8200
    Silverado 4.8 - 7900
    Silverado 5.3 - 8900
    (Silverado HD - Not available with mid level V8)

    Towing Top V8 2WD
    Tundra 5.7 - 10800
    Silverado 6.0 - 10300
    (Silverado HD 6.0 - 12900)
    (Silverado HD Duramax Diesal - 15800)

    Towing Top V8 4x4
    Tundra 5.7 - 10500
    Silverado 6.0 - 10500
    (Silverado HD 6.0 - 12700)
    (Silverado HD Duramax Diesal - 15500)
  • drfilldrfill Posts: 2,484
    This is only the first salvo.

    The 2010 Tundra HD will sport at least 800 lb.ft. of torque when it gets here. They use the engine elsewhere, just shining it up, and waiting for everyone else to show their weaker hands.

    Having an ace up your sleeve is quite nice, indeed. ;)

    Playtimes over.

  • pmuscepmusce Posts: 132
    'I’ll go out on a limb here and predict the next gen Tundra will offer a rear locker (perhaps optional), a boxed frame, better interior, and some sort of safety system such as the OnStar. And a higher price.'

    I would love to see anyone take you up on this bet.
  • pmuscepmusce Posts: 132
    Toyota was eligible for Car and Driver 5 best trucks and Lost. Toyota also would have lost Motor Trend Truck of the year and NAIAS Truck of Year if they were eligible. I find it interesting that Toyota did not delay production of the Tundra until after the GMT900's were revealed. Had they made their original production date, they would have been eligible.
This discussion has been closed.