33"s/34"s/35"s stock truck with auto trans
 

Ok so I know 35"s look the best but are they really practical for a stock powered truck with an auto trans? I want good looks but also practicallity. I feel a 33 will look a little better than stock, will still handle and tow pretty close to stock, and may with a little rpm drop up top actually improve mileage. 35"s look good but by the time I level it and with the additional rotational mass I think I will hurt mileage and overall towing capabilities. 34" in between the two and maybe the best option. Any thoughts, advice or suggestions??





Oh and is their any way to find what rear end ratio I have? No sticker in glove box, nothing on the door stickers, and nothing on the rear end itself?

I have 35's and the truck runs great. I have 410 gears and probably the reason but never had problem.https://www.dieseltruckresource.com/...m/100_2989.JPG

Looks bethttps://www.dieseltruckresource.com/...m/100_2990.JPGter also.

I have 33's on my truck and I like the look. I like to see some air around the tire instead of completely filling the wheel wells. I did notice a slight performance decrease and mileage decrease but not much. I do think that 35's would be a very noticable decrease in performance and mileage but that is just my opinion.

If you can't find your gears anywhere on the truck you can always jack up the back end, spin your tire one revolution and count how many revolutions your driveshaft spins.

If you don't have listing in the glove box for gear ratio its the standard ratio, 3.73.

Any more than 33's and you run the risk of hurting clutches and TC in normal circumstances. The 35's and towing with a stock trans will just cost you a transmission in the near future. If you tow much weight you won't like the way you have to run it to keep the rpm's up.

Take your VIN to the parts guy at a dealership and have him pull the build sheet. That will tell you exactly what you have, as long as it has not been changed if you bought the truck used.

I tow a race car with the 35's in picture and have no problem at all. And now that I have the smarty it;s even better

I had 35s on mine with 3.73 gears and the 48RE. They looked great and were good off road.

For towing, first gear in the tranny is already too high and the big tires made that worse. OD was so high that it was not used on any grade while towing my trailer at about 7-8,000 lbs. So, efectively, I had fewer gears and worse acceleration away from stops. Finally, I began to slip the lockup clutch towing in the mountains at 1600 RPM. Larger tires require Tow/Haul more to keep the revs up and protect the lockup clutch.

The larger tires also steer the truck much more than smaller ones. So make sure you have the '08 steering linkage upgrade, a good track bar and good ball joints. Adjust the steering box, etc.

If you can live with the look of smaller tires and you want to tow, get the smaller size. 285/70 Toyos are a good compromise between the 265/70 stockers and the 35 inchers.

I run 35s with 3.73s

No performance issues but I don't tow heavy. Keep in mind running 35s will pull your RPM down to around 2000 RPM at 78 MPH.

It works great for fuel mileage in Montana were the interstate is 75 MPH and two lanes are 70 MPH.

However, I definitely wouldn't mind 4.10s.

If I towed more or heavy I would definitely opt for 4.10s.

I would agree that 1st and Reverse are too tall to start with.

How heavy do you tow? I would say if you are towing more then 8k frequently and live in the mountains, you would be better off staying with 285/70s. Anything lighter or if your in the flats, I don't think you will mind the 35s. Thats with 3.73s.

If I had 4.10s I would run 35s unless I was towing over 15k consistently.

Here is a handy gearing calculator

http://www.f-body.org/gears/

OD in the 48RE is .69. Third is 1.0

Also when you plug in tire size, go to a manufacturers website and find out how many revolutions per mile. This will give you a more accurate size. For instance I plug 33.7" into my Smarty to correct my speedometer.

For reference 285/70 w/3.73s result in 2000 RPM @ 74 MPH
35x12.50 result in in 2000 RPM @ 78 MPH

4.10s give 68 MPH with 285s
Or 71 MPH with 35s

I have 35's with 3.73's also, and it does just fine for me. I tow a 10k camper and do just fine. BUT, I am looking at buying a bigger toy hauler in the next couple of years, and I think 4.10's would be a MUCH better choice.

If I had ordered my truck rather than just purchase what was on the lot, I would have got the 4.10's.

Had 35s with 4:10 and truck shifted and drove better but hard on suspension and must be moving to steer. going to 34s as a good compromise, actually 285/75/17 which looks good and should lessen problems. JMO.

Running empty with 3.73' and 35's was fine but when I hooked on to the 5er I didn't have enough RPM's at any reasonable speed to be towing. I would have to shift out of OD for almost any grade or I would lug the motor. I put in 4.10's and it definately tows better with better mileage. I also believe that the intown fuel mileage has increased quite a bit over the 3.73's. Very little,if any, difference in fuel mileage on the highway. I would stick with the 33's, especially if your towing.

Well I checked out the link above and I must have 4.10's. I hit about 65mph at 2K with stock rubber. If I had 3.73 I would be up to 73[laugh] Im not even close. The chart puts me dead on with 4.10s. I still think I am going to get 33s, I dont have the cash for a lift, and I am not a fan of spacer type leveling kits after having a Lorenz on my last truck. The wheel I wanted are on backordered 8-12 weeks :o. So like alot of people I am going to have to go with my second choice XD monsters. Ill post some pics when she is done.

Mine is 4:10 and does the same speed and rpm as yours on stock rubber.

285 bfg km2s

on stock rims, with 373s.. not a wimper from the stock trans... and from my gps they are only 2mph off at 70 mph

Rick