What kind of power/performance loss can I expect when changing from a 35" tire to a 37" tire? I don't really tow anything so I'm only concerned about everyday normal driving, acceleration, mpg, stuff like that. I do have a dp-tuner in truck and 3.73 gears. I like the way my truck drives now and I don't want to sacrifice to much performance, so what can I expect.
If you do not tow its not a big deal the place you will feel any loss is off the line. It is also where you will take a hit in MPG. Try taking off much easier after a stop and you will see improvement in mpg.
I currently have 315/75/16s, I'm thinking about getting 37x12.50r18 and new 18x9 rims. I have a leveling kit installed but will be going to a lift kit if I get the bigger tires.
That's a fairly decent jump in tire size. Keep in mind its not just the overall diameter of the tire you have to consider, but the extra weight of the tire. And the extra weight of the new rims. AND you're going to be less aerodynamic (taller truck, especially if you're lifted). AND have more tire touching the ground which means more rolling resistance.
I know you have a lot of hills up there in Scranton.
My recommendation would be to re-gear, 4.10's at a minimum but its usually not worth the money to go from 3.73's to 4.10's. I think 4.30's would be a better choice.
when i geared my 7.3 i did not feel that the money spent on the gears was as justifiable as i would have hoped. i would put the $1200+ into the motor to get the performance/ mileage gains back.
fwiw i went from a 6" and 35's to a 12" and 38's and put 4.56's under it.
Did it help off the line, absolutely. Was i towing, no. If i was to go back it would have been spent on injectors and or turbo. this is if you have not already bought a trans.
we have the Yukon Gears from Randy's R&P in stock.
what kind of power are you making now, or will be making in the future?
If you EVER plan on doing injectors &/or a turbo...then I would be a little conservative on how much gear you put in there...especially if you are going to (or have) add(ed) a couple of hundred extra hp...
I ran 4.30's with 37" tires (& towed occasionally)...and when I ended up adding a couple hundred more hp...I realllllly wish I had stayed with the 3.73's/// FWIW
but everyone's towing/driving habits are different.
Remove your chip for a day and drive around. That's how your truck is going to feel w/ the 37s and w/ the chip installed. I've already been down this path. Even regeared and it wasn't as good as it had been.
Rim size is a big factor. 20" wheels also really hurt.
All Ive got is a banks(ehhh..whatever...I know what people think of this) big hoss chip that is flashed @100 hp. Which is probably more like 40 rwhp but it drives decent.
Anybody running a 4" and 35's, a 99-04, that has pics?
Don't know about 35's to 37's but I dropped 4 tenths going from the stock 285's to a 6" lift with 37's. As far as gears, they made it nicer for daily driving (I went with 4:30's) but made absolutely zero difference on the track.
I noticed a big drop in power and mpg's when i went from stock to 6" lift 20" wheels and 37" tires. Then after rolling that combo for 2 years i went down to 35's and i could feel a gain in power for sure, i also gained some mpg's back.
I think split eh dif of what the extreme are here.
Go up to 4.10s and you will be fine.
On the loss of MPG 95% of with the bigger tires comes from take offs. Learn to take off super easy and slow and you will get very close if not the same MPG.
I have 4.56 to go in with my 40s from stock if its like my friends I will lose about 3 mpg and 2 if its all hwy over stock no chip etc..
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Ford Power Stroke Nation
2.5M posts
107.3K members
Since 2007
A forum community dedicated to Ford Power Stroke owners and enthusiasts. Come join the discussion about diesel performance, modifications, EGR deletes, troubleshooting, lift kits, tires, wheels, maintenance, and more!