[bostonwindows30]

I have a truck I have been rebuild and was curious on any info I can get as far as theses huge tires on this engine it has a v-6 4.3 vortec with 35's on it.. Is this too much tire for the truck??? Thoughts???? Lifted also....

 

[Mort]

First of all, it's "Vortec," and it's very possible to run 35s with the 4.3. My only recommendation would be to regear to 4.56s in both axles, otherwise your transmission won't last long. You may also think about 4.88s. Your highway driveability will suffer a bit, but turning those big tires with that small engine will be difficult. You need all the help you can get in acceleration.

 

[bostonwindows30]

What if I put smaller tires????

 

[Mort]

A set of 285/75R16 would be about as big as you should go without regearing. It's about a 33.

 

[bostonwindows30]

So putting on 33 should be good??

 

[Billy_Bob]

Note there are other things to consider besides if the engine can handle non-factory specification tires...

That is braking, cornering, and some vehicle electronic modules which measure the rotation speed of the wheels as an input for; shifting, cruise control, speed, leveling, navigation, and even the sound level of the radio.

The newer the vehicle and the more "whistles and bells" the vehicle has, the more things there are which rely on an accurate speed as measured at each wheel. And when you change the wheel/tire size, that also changes the speed those electronic modules "see".

But most important is safety. The factory engineers test the heck out of a vehicle with the factory specification wheel/tire sizes. The vehicle is then fairly safe to drive in most driving conditions. Change the wheel size and height of the vehicle, then roll overs and other nasty things can happen. A lady in such a truck was killed in an accident recently. The braking did not work as it should and she swerved to avoid hitting the vehicle in front of her, and then rolled over.

ABS braking systems rely on accurate wheel speed information.

With that said, the manufacturer and their dealers will have NOTHING to do with modified vehicle like this (because they know it is not safe). I recommend factory specification wheel and tire sizes.

Might want to read the following...
http://www.aamva.org/uploadedFiles/...izedTiresOnAlteredHeightVehicles_Findings.pdf

 

[Mort]

Basically, what that link says, is a truck with 39.5"s will handle worse than one with stock 28" tall tires. I've been around the automotive aftermarket for about 16 years as both a professional and an enthusiast, and that's the first I've heard of that.

Actually, no, that's pretty well known throughout the industry.

As far as putting 33s on your truck, I'd be willing to bet there's probably more Chevys of your vintage with that size tire on it than with stock tires. Obviously, don't drive it like a sports car, but if you have any common sense, you'll be fine. If you don't, than sooner or later Darwin will take care of you anyway.

 

[bostonwindows30]

Thank you for the information, I am going to put 33 on it next weekend.. Should I go smaller?? Might look bad if I put smaller with a lift

 

[Mort]

What size wheel do you have?

 

[bostonwindows30]

They are 16

 

[bostonwindows30]

I think 33 should be fine, what you think?

 

[Mort]

Get 285/75R16, which measures out to be about 33" tall. That'll be just fine. If you go into a tire store and ask for a 33, they'll look at you funny, because barely anybody uses the old style sizes anymore.

 

[bostonwindows30]

Cool thank you for your help, awesome thanks...

 

[Fix'n it]

what gas mileage do you get with that thing ? like 7-8 mpg ?

 

[bostonwindows30]

Made a mistake, they are 17s is this too much? Do I need to change rims also???

 

[Mort]

No, just get 285/70R17 tires. Same overall diameter.

 

[bostonwindows30]

Okay cool, thank you again..

 

[bostonwindows30]

Sounds good, in have right now 35x12.5xr17LT procomp what you suggested is almost the same correct but there 33's which I want..