I've been debating lifting my truck and also getting some bigger tires. Right now i have 245/75r/16 on my 2002 XLT 4x4. I am pretty sure I'm going to get bigger tires probably 285/75/16, but I've seen on some of the posts here that bigger tires may damage your truck. What damage can occur if any from using larger tires? Also is there a great difference in gas milage?

Thanks in advance,

Derek

 

To step up to those tires, it isn't a big deal. It's a very common upsize for someone with 265/70/17's like me, that's what I'm going to. You won't even need the lift, but if you still want it, do it. You won't hurt anything. If you calibrate your speedo, you'll be able to determine gas mileage more precisely, but it won't hardly move. Keep listening for more.

 

If you go with a bigger than stock tire, your going to compromise gas milage. I have noticed a little bit of a decrease with tires that are only 1" in diameter large, and an inch wider. The reason for the decrease is because bigger tires= heavier. The bigger tire you get, the more your engine has to work to get the car moving.
If you want more information I am sure there are threads on here where you can find people that have done the same thing you are planning on doing. Good Luck.

 

Larger and more importantly heavier tires have more inertia. That means, more force to get them moving and more force to stop them. That means more strain on engine, transmission, gears, hubs/bearings and brakes. How much and is itworth it? Everyone has their own value on the large tire size look.

What differential ratio do you have?

 

I did basically the same tire size change on my '97 F150. I didn't recalibrate the speedo and the difference was enough to cost me a ticket. The bigger problem was the loss of power. That truck had the V-6 and a manual 5-speed tranny so it wasn't much of a towing machine to start with, but with the bigger tires, I found myself quite often barely being able to stay in 3rd gear pulling a light pop-up camper. Since I pull a heavier trailer with my '01 King Ranch Screw with the 5.4 and factory tow package, I won't go up in size when I replace tires this summer. Having to recalibrate the speedo wouldn't be that big of a deal, but the cosmetics of filling up the wheel wells seems like a bad trade for the loss of power.

 

I'm debating whether or not i am going to step up to the 305/65R17 or go with the 285/70R17. so over time will i affect a lot of stuff other than gas miliage? or would you recommend just going with 265/70/R17? i have an 04 5.4 Screw FX4. mostly on road use. some heavy winters. i don't tow hardly anything. once in a great while i need too. any recommendations? in order for me to go with the bigger tires i need to get the leveling kit.

 

I do not know what i have for gears, 2002 XLT 4x4 4.6L, I'll check in my manual.

 

if you put 285's on a 4x4 you dont need to level, with the 5.4 you wont notice that much of a difference and its not that much bigger really so you shouldnt have to worry about wear and tear and all that. does fill up the wells and look better in my opinion

285/70/17 - 32.7 x 11.22

265/70/17 - 31.6 x 10.43

and the weight difference is only about 10 lbs. per tire difference is size.....

 

I don't know of any of the late model Ford trucks that came stock with P265's. Seems like P255's were common on 4x4 models. I'm considering replacling my own stock P255/70R17's with P265/70's.

cwbpro69 and APT, given your comments, is this a big deal? I have a 4.6L Screw 4x4 with 3.73 gears. My truck is strong and pulls great, but I just want a slightly beefier look. Given that I don't have a 5.4L, 275's and 285's are already out for me.

 

oh yeah they came with 255....but if i didn't get the leveling kit i would just get the 265's....the last body style had 265....and since ford picked the most retarded size for the new body only tire comes in that size and it's the stock one...maybe another one does....but not bfg or anything like that...and i don't want the stock one anymore, they are crap....-jeff

 

10lbs a wheel is actually vveerrryy significant, at least in my book. I went with 305/50/20's (10lbs more per wheel) and you could tell the car was definately working hard to pull and brake (it was extremely evident). I switched back to 275/55's (just this week...shedding about 8lbs per corner) and the truck feels swift and nimble again. FWIW from a guy that went for it, and then back.

Good luck whatever you decide!
-Travis

 

So tgt, you went back to the stock rims? The extra weight must have been there, in the 305 tire width, and perhaps just the new tire's composition. According to my calculations, this is the difference in height and width for a 4x4 Lariat:

Setup -- Width -- Aspect -- Wheel -- Width In. -- Sec. Ht. -- Tot. Ht.

Custom -- 305 -- 50.00 -- 20 -- 12.01 -- 6.00 -- 32.01
Stock -- 275 -- 65.00 -- 18 -- 10.83 -- 7.04 -- 32.07

Your total height is about the same, and your stock width is just about 1.25 " less than your custom setup. Is that right?

 

Oops, sorry that didn't post properly. I don't know how to keep the fonts from repositioning on this site, so let me know if you need a clariffication.

 

hawg man , I ahve the 4.6L you think ill be workign to hard if i go with 285's?

 

I had the 20" stock wheels, 275/55/20's, sorry for any confusion...here's what I did:

1) From Stock
2) Went to 305/50/20" Falkens and Kero wheels (the tires alone weight 48.9 lbs each).
3) Swapped the Tires back to Hankook, 275/55/20's (40.9 lbs each) on same Kero Wheels (in my sig)

An 8lbs difference per wheel/tires alone.

Hope that clears things up.

-Travis