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Ok need some help. Ive searched and searched on a lot of different sites and all over the web what the largest tire that i can run is, ive found a lot of people saying one thing will fit then others saying it wont fit and so on. So does anybody actually have real experience with this setup running like a 36x15.5 or a 37x13.5? Ive even seen somone say they were even running 38x15.5 but didnt ever see pics or proof of that. My setup is an 04 f250 with the v10, 6" lift and currently running 35x12.5 on 20s with about a -33 offset is what im guessing (+18 offset wheels with 2" spacers) any help and pics would be appreciated, dont want to go spend a couple grand and then be stuck with something that doesnt fit. And i do want to keep functionality with no rubbing. Pics showing current tire setup and how much room there is. Thanks!
I can't answer your question with any certainty, but...
I have always been successful putting tires on vehicles that nobody said would fit just because I got out there and did a lot of measuring. Jack the vehicle up and turn the wheel lock to lock and measure off your existing tire/wheel combo. If you are just changing tires it should be easy to grab a straight edge and look for potential contact points. That's what I did to make sure 37's fit on my truck and I have had no issues. I'm currently doing the same thing for my Mustang...trying to fit some 335/30/18's under the back of a fox body convertible.
I can't answer your question with any certainty, but...
I have always been successful putting tires on vehicles that nobody said would fit just because I got out there and did a lot of measuring. Jack the vehicle up and turn the wheel lock to lock and measure off your existing tire/wheel combo. If you are just changing tires it should be easy to grab a straight edge and look for potential contact points. That's what I did to make sure 37's fit on my truck and I have had no issues. I'm currently doing the same thing for my Mustang...trying to fit some 335/30/18's under the back of a fox body convertible.
Didnt think of that thats a good idea ill try that. I should jack it up from under the axle to get those measurements correct?
Didnt think of that thats a good idea ill try that. I should jack it up from under the axle to get those measurements correct?
Yeah. I would jack under the leaf spring pads on the axle and support with a jack stand just in case. Just make sure you leave enough room to turn the wheel lock to lock.
They do make a tool to do this, but I am too cheap to buy one when I can do the same thing with a straight edge and measuring tape.
Yeah. I would jack under the leaf spring pads on the axle and support with a jack stand just in case. Just make sure you leave enough room to turn the wheel lock to lock.
Awesome ill try that out and see what i can come up with thanks!
I went back and re-read your original post. It sounds like you specifically are looking to go for a wider tire, right? If you're just trying to going taller (e.g. 37x12.5) you should be golden assuming you have no problems now with your existing 35x12.5.
But yeah, if for some you're looking to go wider (to each their own ) with your current wheel/spacer setup, then start at the rear while it's resting on the ground and measure how much clearance you currently have between the inside of the tire and whatever it's nearest to contacting. Then go to the front, turning the wheel to full lock one way, measure clearance, then the other way, and measure clearance. I'm not sure if there's any advantage to jacking it up, but if you make sure both sides are on jack stands at the same time I guess you avoid making black marks in your driveway (or just do it on the street or in a parking lot nearby or whatever). It would help to have a friend hold the steering wheel against the lock.
If you really wanted to get into it, you would need to do it while cycling the suspension. Get one corner lifted as high as it can get to max out travel (to the bumpstops preferably, assuming they've been extended to account for the lift) and see what if anything the rear tires are getting close to and the same for the front at each opposite lock. This also assumes you never air down for off roading such as for sand and such.
Regardless, once you're done, you know that if you have maybe an inch of clearance at the extremes then maybe you can get away with another inch wider tire (half an inch outboard and half an inch inboard) and still have a little clearance, but you're pushing it. Or if you have 6" of clearance then knock yourself out with wide tires
I went back and re-read your original post. It sounds like you specifically are looking to go for a wider tire, right? If you're just trying to going taller (e.g. 37x12.5) you should be golden assuming you have no problems now with your existing 35x12.5.
But yeah, if for some you're looking to go wider (to each their own ) with your current wheel/spacer setup, then start at the rear while it's resting on the ground and measure how much clearance you currently have between the inside of the tire and whatever it's nearest to contacting. Then go to the front, turning the wheel to full lock one way, measure clearance, then the other way, and measure clearance. I'm not sure if there's any advantage to jacking it up, but if you make sure both sides are on jack stands at the same time I guess you avoid making black marks in your driveway (or just do it on the street or in a parking lot nearby or whatever). It would help to have a friend hold the steering wheel against the lock.
If you really wanted to get into it, you would need to do it while cycling the suspension. Get one corner lifted as high as it can get to max out travel (to the bumpstops preferably, assuming they've been extended to account for the lift) and see what if anything the rear tires are getting close to and the same for the front at each opposite lock. This also assumes you never air down for off roading such as for sand and such.
Regardless, once you're done, you know that if you have maybe an inch of clearance at the extremes then maybe you can get away with another inch wider tire (half an inch outboard and half an inch inboard) and still have a little clearance, but you're pushing it. Or if you have 6" of clearance then knock yourself out with wide tires
Awesome thank you! That makes sense im going to measure it all when i get off tonight and see what i have to work with. I dont specifically want a really wide tire just something that fills the fenders more. I want to go to a 37" and a little wider im just not sure i want that gas mileage with the v10 lol thats why i was wondering about the 36"
Gas mileage won't change much at all as long as you're geared correctly for taller tires. Wider tires, on the other hand, might make a small bit of difference. Either way make sure that your speedometer (and thus odometer) is corrected for the nonstandard tire size so that you can get accurate measurements. This shouldn't be an issue if you're geared correctly, but some consider a re-gear to be optional and too expensive to bother with.
Gas mileage won't change much at all as long as you're geared correctly for taller tires. Wider tires, on the other hand, might make a small bit of difference. Either way make sure that your speedometer (and thus odometer) is corrected for the nonstandard tire size so that you can get accurate measurements. This shouldn't be an issue if you're geared correctly, but some consider a re-gear to be optional and too expensive to bother with.
Yeah i havent re geared yet im still running the 3:73s i believe. Want to do a gear swap but thats not it in the budget right now having to do both front and rear gears is expensive.
Yeah i havent re geared yet im still running the 3:73s i believe. Want to do a gear swap but thats not it in the budget right now having to do both front and rear gears is expensive.
what kind of mpg are you getting right now? I was getting 11 hwy with 4.30 gears and 35's(34.8").
I went down to a 33" tire without much change so I did the freespin hubs, electric cooling fans and a sct tuner. I'm now getting 13.8mpg.
I was getting 14.4 but I installed a bbk throttle body and it went down a little. I've been thinking of going up to a 37" toyo mt but I'm not sure I want to loose that much mpg and might just go with their 315/70/18 (35.7)" tire instead
what kind of mpg are you getting right now? I was getting 11 hwy with 4.30 gears and 35's(34.8").
I went down to a 33" tire without much change so I did the freespin hubs, electric cooling fans and a sct tuner. I'm now getting 13.8mpg.
I was getting 14.4 but I installed a bbk throttle body and it went down a little. I've been thinking of going up to a 37" toyo mt but I'm not sure I want to loose that much mpg and might just go with their 315/70/18 (35.7)" tire instead
Last time i checked i was getting about 10 mpg mixed driving. Its terrible. The shop here in town wants to charge $2,200 to do front and rear gear swap to 4:10s
Last time i checked i was getting about 10 mpg mixed driving. Its terrible. The shop here in town wants to charge $2,200 to do front and rear gear swap to 4:10s
you'll definitely need a re-gear for 37's. you can free up some mpg with some headers and a free spin kit.
the free spin kit freed up the most mpg for me but the kit is in the 2200 price range plus installation.
I'm in the process of finishing up a installation of a set of banks headers. I'm hoping to see a little more mpg increase with them
05-17-2016, 05:59 PM
) with your current wheel/spacer setup, then start at the rear while it's resting on the ground and measure how much clearance you currently have between the inside of the tire and whatever it's nearest to contacting. Then go to the front, turning the wheel to full lock one way, measure clearance, then the other way, and measure clearance. I'm not sure if there's any advantage to jacking it up, but if you make sure both sides are on jack stands at the same time I guess you avoid making black marks in your driveway (or just do it on the street or in a parking lot nearby or whatever). It would help to have a friend hold the steering wheel against the lock.