I have 2000 f150xlt scab 4x4 with the 5.4 and I want to put 285/75/16 tires on my truck. I know that they will fit, the kicker for me is that my truck has 3.31 gears. I have read a lot of these forums and I still have not found anyone else that has 3.31 gears with a 5.4 but me, everyone has either 3.55 or 3.73. I dont plan on towing anything and wont haul anything heavier than my four wheeler in the bed (600 lbs or so). I do however like to go offroad, especially during hunting season, but I know my limits and will not push the truck up trails that seem iffy. I dont expect the truck to be a racecar and I dont do burnouts so I dont care if moving up to 33's will slow it down some. I just want to hear peoples opinions or experiences with this engine/gear combo with bigger tires. Or an suggestions you guys might have.

Thanks, Jim

 

Here is a Pic of the truck as well.

 

You're probably gonna get a few different opinions on this, but I say no. It will be an impact. Will be undriveable?? Absolutely not. Will it damage anything?? Absolutely not. Will it be fun to drive?? Absoluely not. Will you notice the ding in performance and everyday driveabilty?? Absolutley. Gas mileage will suffer also, possibly significantly. I didn't like my 33's with 3.55's; can't even imagine how bad it'll be with 3.31's.

 

Fords modular motors (4.6, 5.4, 6.8) all make their power at higher rpms than the pushrod engines of old. 3.31 is too tall for these types of engines. 33's will only make the gearing taller. You can do it, they will fit, but you will be a long way from the power band of the truck. If you don't tow or haul much, maybe you won't care. If you like having access to the engine's power, you will care.

 

I'm not saying you're wrong or anything but I always thought it was the opposite of that. That the 5.4 made peak torque at 2500 Rpms. I'll agree that 3.31 is too tall of gearing for the trucks. I think it hasn't bothered me much yet because I don't tow with it, I would love it if it had 3.73 limited slip. I just can't afford to regear right now. Would a tuner be of any benefit at all if I were to go ahead with the bigger tires?

 

Ever heard the saying there's no substitue for cubic inches? Well, I like to say there's no substitue for proper gears! No, a tuner is not a replacement as it doesn't change the rpm operating range of the engine; it would be a band-aid to the true problem. And for what a tuner with a good program costs, you're not far off from saving up the money to get gears! And it's not just all about towing, it's about the normal, everyday driveablility of the truck; the fun factor will be gone.

 

This is true except for the 4.6 that one is rev happy.. And from what I know the 6.8 is very low torque not rev happy at all.

 

Having owned a 6.8, I can tell you that the v10 power band is a lot higher than what most people are used to. Do some reading in a v10 forum, and you'll find that these engines make a lot of power, but you have to be willing to let it scream.

 

Dang. From what I read after, I think,ishootstuff did a v10 swap he said it pulls great down low but falls on its face at high rpms. ..maybe it was the gearing..

 

hmmm well this sucks. I have heavy 245 75 16's on there now (cooper st maxx) and they didn't seem to do anything to the trucks performance, but they aren't that much bigger than the little donuts the truck came with stock. I'll probably end up going with 31's next time and calling it good. Or if I can't find a cheaper set of 285's I may go ahead and mount them and see how much they affect the drivability of the truck and keep the old tires I have now incase I don't like how the 285's are. Thanks for the help.

 

Make no mistake, the v10 does pull great down low, it just makes maximum power at higher revs than many are used to. Compared to a 5.4, the 6.8 has a lot more grunt.

If you are towing heavy up hill, most people find that they have to wind that modular up, a very different experience from diesels or ohv v8's.

 

270,
I too had the 3.31:1 gears in my 2002 extended cab 4x4 4.6 when I purchased it back years ago. The truck came with the stock 235/70-16 tires, and that combo made me re-gear my truck, for my towing purposes.
I re-geared to 4.10:1, an currently have two sets of tires I swap between. I run either 265/70-16 or 285/75-17 tires. with the 285/75-17 tires, the truck pulls and acts just a bit better than the setup (235/70-16). with the 265/70-16 combo, it feels like it is right on the money with acceleration, gas mileage and all around drivability. the 265 size combo yields me between 13.3-14.2 mpg city, up to 16-17 mpg highway. with the 285 tire size combo, yields me a bit lower mileage-13.1-13-5 mpg city and up to 16 mpg highway.
The 4.10:1 gears work great for me, as I spend time up in the mountains on fire roads and such, and either tire size also works.
Hmm, anyone around or near you have a set of the same size tires that you want to try out mounted on 5x135-16" wheels? just to see if it would work out for you? or some used tires on craigslist.

 

Yeah that's kind of what I'm looking on Craigslist for is a cheap set of 285's that still have a little life left in them. And try them and see if I want to go with that size or go back to my 245's.. They just look wrong on the truck.