tire size vs mpg/performance

[xill]

hey all, i'm looking at some new wheels and tires and need a bit of advice. im looking to go with 20s on 35"x12.5" Grapplers with a 5-6" lift, but also like the look of 22s on 38" or 40" Grapplers (with an additional 3" body lift). i have an '07 4.7L QC 2WD and will be travelling about 700-800 miles a month (about 90% of this being highway miles). I'll also be wrapping my truck to promote my business and make better use of the attention it will be getting. But my question is regarding the performance and MPGs of my truck with the 38s or 40s. First, can my truck even handle these size tires without being a 4x4 or having the 5.7L? I dont want to put major strain on my motor or tranny. Second, is there a huge drop in MPG between 20s on 35s and 22s on 40s (or 38s)? thanks

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[MikeHTally]

Put the money in the business, not your truck. Since your mileage is highway, larger diameter tires will help the mileage, but start-up torque will suffer.

[ramhunter9]

Originally Posted by xill

hey all, i'm looking at some new wheels and tires and need a bit of advice. im looking to go with 20s on 35"x12.5" Grapplers with a 5-6" lift, but also like the look of 22s on 38" or 40" Grapplers (with an additional 3" body lift). i have an '07 4.7L QC 2WD and will be travelling about 700-800 miles a month (about 90% of this being highway miles). I'll also be wrapping my truck to promote my business and make better use of the attention it will be getting. But my question is regarding the performance and MPGs of my truck with the 38s or 40s. First, can my truck even handle these size tires without being a 4x4 or having the 5.7L? I dont want to put major strain on my motor or tranny. Second, is there a huge drop in MPG between 20s on 35s and 22s on 40s (or 38s)? thanks

this thread is all messed up first of all ...38' or 40' tires you got to be kidding anything over35 on any truck is dumb . you will need gears plus allot of engin mods beings that you have a 2wd 4.7 that is ...in a short point your nuts

[xill]

thanks. the truck is my toy, but if it attracts attention anyhow then it wouldnt hurt to slap the biz name on it for a while :P about the better mileage, i was always under the impression that larger tires decrease MPG, but you're saying they'll help on the freeways? *confused*

[xill]

Originally Posted by ramhunter1

this thread is all messed up first of all ...38' or 40' tires you got to be kidding anything over35 on any truck is dumb . you will need gears plus allot of engin mods beings that you have a 2wd 4.7 that is ...in a short point your nuts

well thats why i was asking i like the 35s, but have seen alot of really nice trucks on 37s, 38s, and 40s. tho i have no idea whats involved in running with those sizes other than lifting for tire clearance. thats why i come to you guys for advice being that i'll need alot more than an additional body lift to run those sizes, i'll stick with the 20s & 35s. the last thing i want to do is over-tax my ride

[lxman1]

Taller tires turn slower which makes it act like there is less gear in the rearend which keeps the highway rpm lower.
The stock 275/60R20 tires are about 33" tall. I wouldn't go any larger than 35" and that will probably require a 2" leveling kit for the front. Larger than that and you will be replacing front end parts alot!!

[blakeroberts88]

Is there any point of getting big mud tires and a lift kit on a 2wd truck? Doesn't seem like it would be of much benefit.

[xill]

Originally Posted by lxman1

Larger than that and you will be replacing front end parts alot!!

i'll stick with the 35s then since i really dont have time to deal with repair headaches. these other guys running 38s and 40s must either hardly drive their trucks or have alot of time and money to devote to them. thanks for the heads up

[xill]

Originally Posted by blakeroberts88

Is there any point of getting big mud tires and a lift kit on a 2wd truck? Doesn't seem like it would be of much benefit.

no more of a benefit for my truck than 35s i guess. like everyone else that does it i just like the way they look, but not enough to hurt the ride. i got a 2WD for better MPG on the highway, but i dont like the truck looking like every other Ram either.

[Got_Hemi44]

Originally Posted by blakeroberts88

Is there any point of getting big mud tires and a lift kit on a 2wd truck? Doesn't seem like it would be of much benefit.

A 4wd is in 2wd 98.7% of the time