Towing in 3rd gear rpm high?

[kwslvdo96]

Hey guys new to the towing a travel trailer and I Have a 1996 Silverado extended cab 4X4 with 5.7 Vortec and factory 3.73 gears and factory size tires 265/75/16 and the truck only has 50K original miles. I'm towing a 21ft Wilderness bunkhouse camper dry weight I believe is 3850lbs (at least that's what the salesman told me) My truck loaded with firewood and all the rest of the goodies im guessing I'm towing around 4500 to 4700lbs. My truck can not tow this camper in overdrive without upshifting and downshifting so I was told to just run it in third gear which in this truck the owners manual says to do anyways to keep transmission from overheating. The problem is at 60mph in third gear I'm at 2400 to 2500rpm! The truck pulls it no problem in third gear but the rpm being so high for a long distance is bothering me. I was thinking instead of doing 4.11 gears because I still don't think I could keep it from downshifting of doing 3.42 gears and when I replace my tires to go just one size up and that would put me at 2300 to 2350rpm at 65 in third gear. What do you guys think?

[Nvr2loud]

proxim2020 wrote:
People often think that if they keep the RPMs lower then they're being nice to the motor or do it to save gas. What they are actually doing is hurting the engine by dramatically increasing the engine load. Demanding power at lower RPMs puts incredible stresses on the engine, something that gas motors aren't designed for. It will effectively hammer a motor to death. Gas motors need to rev to make power. The peak HP for that motor comes in at about 4600 RPMs so 2400 is nothing. Keep the revs up and you'll get a lot more use out of your engine.

YES!!!!

Finally someone states it.

I run my 5.3 with 3.42 gears (6 speed) in 4th and under when towing. The engine speed goes up, power is great, fuel consumption is better, and both engine coolant temperature and transmission fluid temperature go down.

When I attempt to use 5th or 6th gear, the temperatures go way up, power to pass or hill climb is gone, and the fuel consumption becomes awful.

[boogie_4wheel]

On my '97 K1500, my last set was BFG AT/KO D-range. I got over 60k miles out of them (and were close to being on the bars) when I sold the truck (with 244k on the truck without engine/trans rebuild). I ran them at 65psi all the time regardless of what I was doing.

[Tachdriver]

Excellent, I did the same with the gauge. At least you know where you stand as you tow.

[kwslvdo96]

I ordered a Glowshift transmission tempature gauge and a billet aluminum dash mount pod so I can keep an eye on the transmission temps while I'm towing my camper. I'm also swapping all my fluids to Amsoil other than engine I'm staying with Mobil 1 there since that's what the truck has had since day 1.

[kwslvdo96]

Ok I'm going to probably end up going with Michelin brand for sure and C rated if possible if not E rated will work and I can just play with the tire pressure.

[APT]

Running an LT E range tire at 40 psi will feel just like an LT C tire at 40psi. Most tire do not come in every size and ever load rating. Focus on getting a quality tire and run the appropriate pressure for your needs.

I am very happy with the Michelin LTX M/S2.

[lbrjet]

LT C is more than enough for any half ton, except the Chevy HD half which is not made anymore. Yes, you should get 60K (or close, some people get more) if you don't get a super aggressive tread.

[kwslvdo96]

I would like to go with a good all season tire, I do live in Michigan and this truck is my daily driver so I want something that is decent on icy and snowy roads. But this truck is just a pavement pounder I do not take this truck off road. Is there a good difference going from a C rated to a D rated tire? I'm afraid to go to a E rated tire because when I'm not towing I don't want to feel like I'm getting my brains beat out? I'm not brand specific either I've just read and herd that Michelins are a good quality towing tire that you can get it 60K miles out of them? I don't want to spend $800 to $900 in tires and only get 40K miles out of them.

[Dog_Trainer]

Look at Michien LT/MS These are a great tire I put them on my 1/2 ton Ford and they are still on my 3/4 ton Dodge. Load range E and you can air them up or down as you tow. The reason to change from p rated tire is the side wall dif. The prated feel squishy as you tow the added sidewall stability in an E rated tire is noticeable.

[JIMNLIN]

The OP has a older 350 chevy so other brands/gears/transmissions don't apply here. I believe he has already received his answer many time over.

Anyhow.... now his question is what brand tires and which load range.

I've used LT E tires on a couple of 1500 trucks some years ago but always went back to a C load range or a 44 psi rated P tire.

If the truck isn't driven in snow/icey/off road a good all season (AS) tire will work.
All of my trucks see this type of driving so I keep a good all terrain (AT) tire on them.
I'm not a brand fan and have used Bridgestones/Michelins/Cooper/Goodyear/Uniroyals/Delta/BFGoodrich/Firestone P and LT tires on my various 1/2...3/4 .....and one ton trucks over the years. Each tire brand has several tire type to choose from. Check out the tirerack.com for brands/sizes/load ranges/tread types availability and prices.

[525pilly]

I often think back many years to when as a kid of 19 yrs I thought I had hit the big time, driving a semi.

The tractor was a '56 Ford F800 "Big Job" with a 272 cid (4.5L) V8, 5 speed transmission, 2 speed axle and air brakes. The factory tachometer was marked with an operating range of 2400 to 3600 rpm, it had to be turning at least 3000 rpm to develop any power. At legal top speed of 50 mph it turned about 2800, but the slightest grade required an immediate downshift and higher rpm. And that was almost 60 years ago, engines have improved drastically since then.

2400 rpm isn't much for your engine, it would actually be happier running faster under load.

[kwslvdo96]

What are the tire options out there that you guys are using? Ive herd great things about the Michelins as far as they wear great and there quiet tire. And colliehauler your correct at 65mph in third gear id be running 2700 to 2800rpm. I'm still trying to decide on the Load range C or D tire and brand. I would like something that is decent in the snow but I don't really want to go with a bulky all terrain.

[SoundGuy]

budwich wrote:
As for the running in 3rd, as other suggest, should be no problem.

Of course, your fuel mileage will be reduced with the higher rpms but gas has gotten cheaper ... 🙂

I've been towing for 10 yrs now with GM's 5.3L engine coupled via the older 4 spd wide ratio transmission to a 3.42 axle, first with a 2006 Silverado and then with a 2005 Avalanche with which I still tow. I always run in 3rd with Tow / Haul engaged and at highway speed with the engine running around 2300 rpm fuel mileage is as good if not better than if running in Drive with the engine lugging around 1500 rpm. Serious upgrades require a manual downshift to 2nd but even when dragging around 5500 lbs I could not only maintain highway speeds but even accelerate, even better now that my current trailer typically averages 4500 lbs. With a 4 spd wide ratio GM tranmsission and either 3.42 or 3.73 one would always want to tow in 3rd with Tow / Haul engaged as that puts the engine in it's sweet spot and help realize it's best fuel mileage return. I would expect the same with the OP's older 5.7L GM.

[Gene_Ginny]

With my 4Runner I always tow in 4th now instead of overdrive. The RPM is about 2200 @ 65 MPH and I found I get almost 1 MPG better gas mileage at the higher RPM. As others said, the engine is running at its "sweet spot".

[budwich]

ktmrfs wrote:
one other item of critical importance. On most transmissions the torque converter stalls at around 1800-2200 rpm. that means, IF you are using a gear that would say need 1800 rpm to run the speed your at, and you put a load on the engine, the rpm will go to 2000 or the stall speed. the result is a large increase in heat buildup in the transmission fluid. One of the worst things you can do is run an automatic at stall speed with lots of slip that means high transmission fluid temps = potential transmision failure.

In the OP case, 2500 is going to be well above stall, maybe 100rpm of slip if it isn't locked up, very good.

great post. OP, get an app like torque and monitor your slip to ensure that your tranny is indeed locking up in 3rd and slipping significantly... sometimes its slightly subtle to see the difference in rpm on your gages.

As for the running in 3rd, as other suggest, should be no problem. I have a trailblazer pulling a 4.5K lbs trailer for 15K miles in 3rd. It pulls find except up any major hills but even then gearing down for the short time isn't an issue. Of course, your fuel mileage will be reduced with the higher rpms but gas has gotten cheaper ... 🙂