toyota tundra

[Silvertip]

Re: toyota tundra

Here's a 5.7 Chevy curve. One can immediately see that this engine design, old as it is, develops 370# of torque but only 292 HP. What's important however is that HP and Torque cross at about 2500 RPM rather than the 5500 in the Toyota. Guess what -- 2000 - 2500 is where this vehicle would cruise at with 3.73 gears in Drive. This is the point where economy vs power comes into play. It's a designers choice as to how you want to bias things. Of even more interest is the fact that Toyota has what looks to be about 315# of torque at 1300 RPM. The Chevy shows 350# at about the same RPM. Likewise there is only 20# difference in torque to 4000 RPM. Think back to the last time you needed to tow anything above that rpm in any gear other than perhaps an intial start to merge with traffic. I'm old enough to have driven every version of this engine design in cars, trucks and boats and to this day it is highly desireable engine for a tow vehicle.

Since the much more modern Chevy 6.0 is closer in displacement to the 5.7 Toyota than the 5.3 (for which I don't have a graph) I'll show that one next.

 

[Silvertip]

Re: toyota tundra

Here's the Chevy 6.0 graph. Once again you will see the HP/Torques cross at about 2500 RPM. Torque is over 300# at 1000 RPM which is very similar to the Toyota. Peak torque is either 409 or 394 depending on the engine code. HP is for all practical purposes the same. Key here is the torque curve. Note that in the Toyota, once you get past that 3500 rpm range, torque falls quite rapidly. On the Chevy, its still crowding 400# at 5000 rpm. Torque at the low end is about even but the Chevy gets down to about 1000 RPM where the Toyota is at that 1200-1300 rpm range. Sorry if you were bored by this but one needs to understand not only what torque and HP does for you, but what it does for you in the intended application. In the end, you pay your money and buy what you like. If I could design a tow vehicle for myself it would a be "heavier duty" Colorado/Canyon crew cab size with a 4 or 5 cylinder diesel, five speed automatic, turbocharged and intercooled with about 350# of torque. Even a four speed automatic would work but I would prefer it with a two-speed rear end. It would deliver great fuel economy loaded or unloaded and handle loads to 4000 or so with ease. That size and that load represents the needs for the vast majority of households with recreational toys to tow. Obviously those with bigger toys need bigger vehicles. I'm done and won't bother you further. Thanks for watching! o

 

[bruceb58]

Re: toyota tundra

The Toyota graph has a different scale than the GM graphs. It makes the torque fall-off look more than it actualy is. Would be better to have all the engines on the same graph.

I looked at a few points and it looks like the Toyota engine is very similar to the GM5.7

It is generally accepted that an engines sweet spot is where horsepower and torque cross

Since horsepower = torque * rpm / 5252, the graphs should only cross at 5252 RPM.

The sweetspot of an engine is really the point of peak torque.

 

[Silvertip]

Re: toyota tundra

So you are saying we should all be towing at upwards of 4000 rpm? If we towed at what you consider the sweet spot, none of us could afford the gas bill. Besides, in GM engines the two are not that far apart. Once again it boils down to where and what designers want to compromise. You can bias toward, economy, performance or somewhere in between. You can't have all three -- or even two of the three in most cases. I like to use the steam engine as an example of HP vs torque. A steamer has max torque at zero rpm (stalled against its load) regardless what the formula says. But at max torque it has zero horsepower because there are no rpm and hence no movement of the engine. Because the engine is at max torque and not moving, max torque cannot be the sweet spot unless max torque is what you consider important to the application. Ain't this just like politics? d

 

[bruceb58]

Re: toyota tundra

No..wasn't saying that at all...just noting where the sweetspot is. The sweetspot is not the most fuel efficient spot.

Actually a more important parameter is the flatness of the torque curve so that no matter what the RPM you are driving at, you can accelrate without the need for changing gears. That jives with what you were saying about a tranny hunting for gears.

I pretty much agree with most of what you said above.

 

[bruceb58]

Re: toyota tundra

It is interesting that if you look at the bore and stroke of the Toyota 5.7L engine and the GM 5.7L engine, you would actually predict that the Toyota engine might produce its higher torque at the lower RPMs since it is more of an undersquare engine vs. the GM which is an oversquare engine.

Regarding OHC..Having OHC does not have anything to do with what an engine's RPM peak torque is at. However, an engine that needs to run at high RPM to achieve peak torque needs to have an OHC since a pushrod setup has too much inertia to operate correctly at the higher RPMS.

In the Toyota Tundra engine, The OHC is required for variable valve timing and 4 valves per cylinder, not becuase it needs it because of high RPM.

I am actually a GM guy when it comes to trucks. I do think this Toyota has a lot of promise as a tow vehicle. For towing, I would pick the Toyota 5.7L over the anemic GM 5.3L.

 

[JRJ]

Re: toyota tundra

anyone with experience towing with this truck.

having a hard time finding out it's towing cap.

maybe looking to replace my chev 2500 (don't know why, but I like new trucks)

OLDSPUD, you don't say which model you are interested in.
Towing capacity ranges from 5100lbs to 10100lbs depending on engine and how its equipped.

You can order an 07 brochure from Toyota on line.

 

[Silvertip]

Re: toyota tundra

Bruce -- I agree that use of dual OHC offers nothing other than the ability to allow more intake and exhaust tunability. Four valves per cylinder greatly enhances high rpm breathing so overhead cams are a must as there simply isn't enough room in the valley of a V8 for all the lifters, push rods and a hemi-like valve train for 4 valves. It's obvious the Tundra is a deep breather as it spins into the high 6000's. Again, the value of that in a truck is debatable. As an interesting aside I was just reading a test report on a Corvette Z06, Porsche, Noble, and Lotus. The Corvette would run 198 MPH, was fastest to 60 and would still deliver 26 MPG. The other cars had very high winding engines with deep gears and would kill the Vette between 40 and 70 but that was all they excelled at. Fuel economy (except for the Porshe) was a joke. Isn't it ironic that the Tundra also advertises on TV that its fastest in the 40 - 70 range. Ummm, 4.10 gears I would hope so. 'Nuf said. I've taken too much of everyones time. Nice truck. Enjoy.

 

[bruceb58]

Re: toyota tundra

I think they actually have 4.3 rear ends. The final ratio proably is similar to other trucks taking into account the tranny ratios.

 

[JRJ]

Re: toyota tundra

The 4.0L V-6 and 4.7L V-8 have 3.909 gears and the
5.7L V-8 has 4.100.

 

[bruceb58]

Re: toyota tundra

JRJ,

You are correct. What I saw were the ratios if you get the tow package. This is what you get(pasted from the Toyota website)

V8 Tow Package [2]
Heavy-duty tow hitch receiver, 7-pin connector, Trailer brake controller prewire, Supplemental transmission cooler, TOW/HAUL mode (not available with 4.7L V8), Automatic-transmission temperature gauge, 4.100 rear axle ratio (on 4.7L models) or 4.300 rear, axle ratio (on 5.7L models)

I like that it includes the auto trans temp guage like the 3/4T chevys do.

 

[Rob454]

Re: toyota tundra

My buddy has a 05 tundra with a 4.7 v8. i towed my boat one time with it cause my truck was getting tires that day and we were going fishing. its a 19 foot bowrider. it towed it just fine. little sluggish off the line but we had a ton of crap in the back of the boat and the bed
Rob

 

[steelespike]

Re: toyota tundra

I won't argue about Towing but I will suggest this.
Consumer reports list of unreliable vehicles includes Avalanche 1500 03-04,Avalanche 2500 02-03.Silverado 1500 4wd 03-06,Silverado 2500 4wd 03-04,Silverado 2500 turDsl 4wd 01,03-04 While these may not be exactly what your towing with the trucks are all close cousins.Chevy has 24 rows of vehicles to avoid.
GMC all the same trucks.Ford and Dodge roughly the same vehicles The only Honda listed is not built by Honda, Toyota has no vehicles listed.
Reliable used vehicles typical list has 1 or 2 Chevys
covering 1 or 2 years 10 Toyotas covering multiple years.
I think I know why Chevy,GMC,Dodge,and Ford are struggling.
I think I know which truck I want when I want to be sure to get my boat to the water every time with the least service required over the years.

 

[bruceb58]

Re: toyota tundra

The consumer reports reliability tables can and have been mis-leading in the past. Very minor issues can give a vehicle a bad mark.

My most 3 recent vehicles, all bought brand new, have been a 2002 Chevrolet Suburban, A 2004 Ford F-150 truck and a 2005 Lexus GS-300. Guess which one was at the dealer the most under warranty...the Lexus! They werent major problems but would have effected the reliability index.

The Chevrolet Suburban was the most reliable vehicle I have ever owned.

 

[Silvertip]

Re: toyota tundra

I've followed consumer reports since Hector was a pup and I find them very biased toward imports. I, like Bruce, have owned nearly every American brand and several imports but the vast majority of my vehicles have been GM and none, not one, has ever left me sitting at the side of the road needing assistance. Every other vehicle has done so at least once. Honda for example was just called on the carpet for knowingly building cars with inaccurate odometers. The net effect was that the cars were logging more miles than actually traveled. Net result is leases end earlier, warranties expire earlier, and, although I can't find the article, Honda was also accused of informing dealers to fix things they detect (under warranty) without telling owners. While that may seem noble on Honda's part, it also would affect reliability ratings if the owners knew about the issue. Car and driver just rated the Tundra third in a five vehicle truck report. They put the Chevy at #1. Obviously what some people feel is important may not be important to others. So buy what you like and enjoy.

 

[steelespike]

Re: toyota tundra

I don't recall mentioning Lexus. GS series has an average reliability rating.Which in my opinion is not good enough.It does have a better than average Satisfaction rating and resale value.
You say they have an import bias How are you biased when you report actual repair frequentcy reports from owners.They have always roasted The Compact Toyota Pick ups for for poor ride and handling and a flimsy boxs (some of which were made in Texas)Some folks who have inferior cars don't even know it.Years ago I asked a friend how he liked his Chevette He said it was wonderful When I pressed him for details among other problems he mentioned he had the brakes done every year.No problem except he only drove 7,000 miles a year.
My first Toyota,a new 78 Corolla wagon,I kept it for 8 years 130,000 poorly cared for miles it still had its original hoses,and belts,Never flushed or replaced coolent.Still went 6,000 miles between oil changes without adding oil.Tried to buy american in 93,new Jeep Cherokee,A design that had been in production for something like 7 yrs.Off the floor it had leaky water pump,terrible draft under the dash,pasenger door didn't shut riight,then had to replace brakes and rotors at about 13,000 miles,wipers developed about 3 inches of slop,FM side of the radio wasn't right,passenger door never did shut right, and the tailgate button fell out twice.
Got rid of it at 18 months about 24,000 and the brakes were at it again.My 95 Toyota Tacoma, First year of production, did have problems with rear springs breaking
this was evident in the reliability ratings of these trucks.
Other than a new 82 Dodge van (not that great) and the 93 Jeep I've been buying Toyota and Subaru since 78.New every 3 years,Tacomas other than the 95 springs never returned for any repairs,Subarus don't measure up to the Tacomas but still superior to most competitors.Check all the import reports I think you will find no bias.

 

[Silvertip]

Re: toyota tundra

Have you every noticed that problems owners of imports have (and they do have them) are not real problems but are considered "flukes" so they must not count? Have you ever heard and import owner say I'll never own another American car/truck and then say their tranny failed but it must have been a fluke? Or the oil sludged up in my Toyota ruining the engine so the oil must be to blame -- and we now know that wasn't the case. Toyota, Honda, and Nissan are all experiencing quality issues as they try and flood the market with an ever expanding list of models. My daughter bought a new Honda Van after she complained about an annoying hum from the Chevy Venture fuel pump. The Honda turned out to be a much bigger problem than the Chevy. That went down the road for a Mazda 6. Ya! Tranny problems -- twice. Brakes at 20,000. At 25 MPG max the Mazda is a gas hog compared to my Impala and its far less roomy. I can live in the trunk of my impala. Sorry about the Consumer Reports rant but those ratings are based on the first 90 days of ownership. Most marriages are happy for that long.

 

[steelespike]

Re: toyota tundra

Generally speaking the Mazda line are not particularly reliable overall average at best.The Mazda 6 has a worse than average satifaction, average reliability,and average resale.The Honda Odyssey has average reliability No one said Toyota is infalable and the V6 problems show up in the Engine section of the ratings for those cars.No one said all Chevys/Fords etc are bad But based on actual customer experience unfortunately generally American reliability is average at best.No one said all Japanese are good some are horrible.Your Impala has average reliability and satisfaction and is reccomended by consumer reports. "Average reliability" is 3 steps below the best rating there are only 5 steps.
Keep in mind these ratings I'm talking about are generated buy the owners actual ratings also keep in mind every vehicle and item tested by Consumer reports is pruchased by them not bought on a special deal or loaner.I reported my spring problem to consumer reports.If you and your daughter were members you could report as well.If a car doesn't recieve enough good or bad info it won't be rated.
I suggest you stop at the library and check out the latest 2007 auto edition.You'll be surprised what you find.For instance Mercedes Benz doesn't even reach high enough to reach average. Mercedes mean is minus 123 bottom is -200.Toyotas mean is+ 48 best is +95
.