First Tow with new TT, 8400 lbs

[bluwtr49]

Originally Posted by ramoine

bluwtr49 said:
(quote)The engine isn't that much more powerful but coupled with the rear gears should make it a good performer.(quote)


I beg to differ on that , as well as more Torque .

Sorry, I don't consider 15 % more HP and only 7.5% more torque to be as big a differance as going from 3.73 to 4.3 gears. The combo is what makes the differance not just the power increase.

[ramoine]

Tundra has the better engine and torque curve . The Jeep was never built with the purpose of towing , it was engineered for getting dirty once in awhile .
I had one with the 5.7 and it no way tows better than the Tundra not even close in my experience .
The tranny in Jeep GC was not the greatest , had 2 replaced and it barely towed up to it's rating , so I honestly can't see you saying it pulled better up a grade than the Tundra under any circumstances .

By the way 15% and 7% are huge numbers considering they both are 5.7 's .

[bluwtr49]

Originally Posted by ramoine

Tundra has the better engine and torque curve . The Jeep was never built with the purpose of towing , it was engineered for getting dirty once in awhile .
I had one with the 5.7 and it no way tows better than the Tundra not even close in my experience .
The tranny in Jeep GC was not the greatest , had 2 replaced and it barely towed up to it's rating , so I honestly can't see you saying it pulled better up a grade than the Tundra under any circumstances .

By the way 15% and 7% are huge numbers considering they both are 5.7 's .

I don't believe I ever said or implied that the Jeep towed better or even close. What I am saying is that if the gear ratios were the same, the power differance wouldn't be that great....torque pulls, HP holds you there. We can agree to disagree....7% torque differance is just not that great....what about 12 to 17 ft/lbs or so of actual differance. To put the torque differance into perspective...the differance is about the same as 2 21" lawnmower engines.

You're correct in that the Jeep wasn't designed for towing but the 5.7 was. There are a heck of a lot more HEMIS towing heavy loads then there are Tundras. The Ram HEMI both 1/2 ton and 3/4 ton with 4.11 or 4.33 rear gears are great towing trucks. The Tundra with a newer engine design has the power advantage this year. Next year, who knows.

I sure would like to find Dyno curves for the Tundra. I keep hearing the claims about super broad curves but I haven't seen the data.

[ramoine]

I'm still looking for a Dyno sheet , but read this for now until I can find a Stock dyno sheet

Full Test: 2007 Toyota Tundra Double Cab Limited 4x4

[bluwtr49]

Originally Posted by ramoine

I'm still looking for a Dyno sheet , but read this for now until I can find a Stock dyno sheet

Full Test: 2007 Toyota Tundra Double Cab Limited 4x4

I found a couple of dyno sheets. One for the Tundra 5.7 and one for the HEMI. Both come from after market sites so there is a before and after on each sheet. Looking at the torque, the Tundra curve is real steep below ~3500 rpm then flattens out. By my eyes it looks like the HEMI has better low end torque until the Tundra gets into it's power. Then they appear pretty similiar with the Tundra about 15 ft/lbs greater. At high rpm it looks like the Tundra may be less then the HEMI but it's tough to tell with the resolution and differant scaling.

At 3250 (or there-a-bouts) the HEMI may actually have more torque. But the low end grunt seems to be in the HEMI favor then the Tundra takes charge as the rpm's build.

I certainly don't think that the Tundra has a broader and flatter torque curve, if anything it appears the other way around.

[RIjon]

Never EVER trust a dyno sheet from the facility trying to sell their products.

Dyno sheets are SOOO unreliable when doing comparisons unless the dyno tests are being done on the SAME dyno, same parts, same weather,same elevation, same dyno type, same software, same operator, etc....

There are way too many variables to account for. I have have spent far too much time at dynos all over this country. Bottom line is they are fantastic for a baseline, but by no means are they the last word.

Just something to think about when reading these things.

[bluwtr49]

Originally Posted by RIjon

Never EVER trust a dyno sheet from the facility trying to sell their products.

Dyno sheets are SOOO unreliable when doing comparisons unless the dyno tests are being done on the SAME dyno, same parts, same weather,same elevation, same dyno type, same software, same operator, etc....

There are way too many variables to account for. I have have spent far too much time at dynos all over this country. Bottom line is they are fantastic for a baseline, but by no means are they the last word.

Just something to think about when reading these things.

I don't disagree at all but it was the best I good find. In some respects I was more interested in the shape of the curve then the actual numbers but the case of the HEMI, the numbers look about right with other data I've seen. The low Tundra torque at 3200 and then an abrupt increase jibs with my limited experience where it really bogs down if I can't get the rpm above 3500.

In both cases, the peaks are roughly 20 percent less then advertised flywheel specs, so I figure they're probably pretty close.

Would love to see better data if it exists. I'm an engineer so if it ain't got numbers it ain't real. Seat of the pants dynos mean a little less then scat.

[ramoine]

Sorry bluwtr49 , I have'nt found any real stock numbers for either , bit I'm still looking .
I really can't believe they are'nt plastered on the Net. somewhere , LOL !
I'll keep looking though , and will post them when , and if I find them .


Thanks for your patience , Bill.

[OU812]

The power difference is almost irrelivant, it isn't that much. It isn't even enough to really tow a mph or two faster.

I find it interesting that when you really need to keep the revs up but not too high, that there isn't as good of a sweet spot on the tundra. I've towed 11,500 with my 1500HD GMC. I've got the 6.0, 4L80E tranny with 4.10's. There's some very steep hills where I live. I've been on the road that passes through the Rockies and our hills are that steep, just a lot shorter. On this hill, it's about a half mile long. I floored it and I easily held 60 mph. I probably won't do it again but I wasn't expecting the truck to be able to do that.

I'd have to say the motor is built to rev. You should have no troubles running at high revs for long stretches, just watch the gagues.

As for the dodge you can say what you want, but that motor is bad a$$. A lighter vehicle, a lower ration out back in second gear and I really think it could easily hold it's own with the tundra. The only question is for how long. It's just not built to do that, and the tundra is.

Bottom line all of the trucks available will tow anything you want, it all comes down to how much you want to pay and how fast you want to tow it. To me I think we are at the reasonable limits of both and are asking for trouble going past them.

[ramoine]

Originally Posted by bluwtr49
I'm not saying it can't be done, just that you need to be cutious. My Crewmax only has a payload of 1340 lbs or so and that's pretty easy to exceed. 4X2's, DC, and etc have higher payloads.

The chap with the 5th wheel paid close attention to his pin wt and the additional cargo he was carrying, in other words he did his homework to ensure that everything was set up properly. I don't doubt that the Tundra will tow 10,000 lbs but whether or not it tow it well depends on what you expect, the amount of towing you'll be doing, and the expected terrain.

Just be safe.
Member
bluwtr49

Join Date: Jul 2008
Location: Green Valley, AZ
Posts: 43
(Quote) Yeh, I've read reports of high load towing but most have them have been for very short distances and/or relatively level terrain. The Tundra is good but it ain't that good. After towing my 8400 lbs, there is no way I would consider 10K. For one thing the payload capacity is so low, a 10K TT tonque wt would more then exceed the limits.

Of course, the definition of "Good" may be a subject of discussion all in itself. Guess it depends on your standards.

You do not want to tow without using the tow/haul. The shift points and engagement pressures change dramatically. Yes mileage may suffer but the tranny will thank you for it (Quote )


There are plenty of towing reports that state they were long hauls , some live in the mountains and have not complained about the Tundra's capabilities .
It seems to me that this trailer is quite abit heavier than your used to , and along with a new truck you're not used too . You're making your judgement based on your experience with a lighter setup , not from any long term towing with your Tundra .
Stop telling new people that it won't tow a heavy load , because it will .
Thanks , Bill

[cadams1224]

Originally Posted by Smed

I'm getting a troll feeling here.

I have a LOT of trouble believing a vehicle with half the tow rating, much less horsepower, a much narrower power band, worse brakes, 3.73 gears, and a much less advanced tranny is the better tow vehicle.

Let me reiterate - you sir are full of shit.

I love my Tundra

[Gr8one69]

I have a question for you bluwtr49. No where in your posts did it mention you using the tow/haul mode. Did you use it at all in your towing so far and if so, what was the outcome? Just curious if that may have been the reason for your towing issues. Another question that pops into my head is if you purchased it 10 days before towing, was this new off the lot or used with what mileage? Was the engine even broken in before towing with it?

[bluwtr49]

Originally Posted by Gr8one69

I have a question for you bluwtr49. No where in your posts did it mention you using the tow/haul mode. Did you use it at all in your towing so far and if so, what was the outcome? Just curious if that may have been the reason for your towing issues. Another question that pops into my head is if you purchased it 10 days before towing, was this new off the lot or used with what mileage? Was the engine even broken in before towing with it?

Yes, I use tow/haul anytime I have the TT hooked up. IMHO, it's sheer folly not to use it.

When I left Idaho Falls with my 6,000 lb TT I only had 500 miles on the truck and took it real easy. Outside of a couple of steep hills, it's pretty easy drive. When we picked up our new 8400 lb TT in Missoula, we had 800 miles or so. I suspect the engine isn't broken in yet but in my experience that really doesn't make much differance. Modern engines will do what it will do pretty much from the get go.

What I didn't realize until I found some dyno curves is that the engines power curve is really not that flat and the HP is a bit peaky. The flat spot in the torque curve occurs in the worse possible rpm range for pulling hills. Now that I know about it I will have to adjust my driving habits to avoid getting bogged down. Probably use 2nd gear to get me past that point.

While I'm willing to try it in "D", I suspect it won't be very pleasant driving with all the shifting. Tough to take a nap with all the commotion. (Not me, my wife)

In some respects, the tranny gear ratios are not optimized for the power curve. 2nd is a little too low and 3rd is a little too tall. Closing that ratio a bit would help immensly. The Jeep kind of had it right. The 545 tranny is really a 6 sp but it has two 2nd gears.....one for acceleration from a standing stop and the other for downshifting from 3rd and that 2nd was perfectly matched to the torque curve.

[tundratom]

Dick -- I do not recommend towing in D. Especially on hills. Somewhere in the manual it recommends towing in sport mode. The tranny will shift too often (and wear it out). I leave it in 4 on most roads (sometimes 5 if really flat and no wind). Uphills are 2/3. Down hills is also 2/3.