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I have a 2008 Ford Super Duty 250. I changed the size that originally were on the truck from LT265/70R17 to 275/65R20
I know it throws my speedometer off right now so my question is how do I fix it so my speedometer is correct again or should I just keep The Originals on and find new rims for it the rims were rusted so bad that they're actually shot and I was having a hard time finding rims for that truck. But I do know the 2008 this truck here came with that 20 inch rims size tire just not the truck I have did if that makes sense to anybody.
My lazy solution is that I normally just calculate the difference and just mentally keep track of it while driving. Back of napkin math says your difference is about 7.7%, so when your spedometer indicates 60 you're actually going ~65mph, when it indicates 30 you're actually going ~32mph. I don't have any actual answers as to getting the spedometer on the cluster to read correctly.
There's a software program called FORscan that mimicks the Ford IDS program. There is a long thread on it in the 6.7 Powerstroke section. You can get in there and change your tire parameters so the speedometer reads correctly...
That is one nice thing about trucks using a speed sensor, it can easily be fixed. back in the day you had to change a nylon/ plastic gear and hope for the best. Today, you can get it dialed in exactly.
I use autoeginuity (pre-forscan existence) I have the items to use forscan, just have't looked into it
the bad thing about guessing as jbolt said is it is't a set value, it's on a sliding scale...the faster you go the bigger the difference
I've never used FORscan either but want to learn at one point. If I ever go with a Titan 50 gallon tank like I want, I'll have to but there's some great guys in the 6.7 section who would help out...
I'm starting to think maybe I should of stayed with the size that came with the truck. Not sure if it looks good with the bigger tires on it.
Why not? The higher trim level F250s come with 20 inch wheels. From the pic, the 20 inch rear tire looks a little taller but yeah, the front has a taller side wall is all.
I personally am not a fan of 20's on a truck unless you have big tires...but it doesn't look too bad...It should handle corners better but might be a little rougher ride possibly....I grew up in the era of 15's or 16.5's and my dually has 16's. I have 17's for my 76 project but I wouldn't go any bigger than 18's on anything I own, but that's just me
Why not? The higher trim level F250s come with 20 inch wheels. From the pic, the 20 inch rear tire looks a little taller but yeah, the front has a taller side wall is all.
yeah I haven't put the front 20-inch ones on yet I'm still cleaning those two rims and I got to find two tires for them yet. But other than that I just want the truck to look nice so I was trying to look for opinions between that 20 inch and the original 17 inch that's on the front
My 96 had 16 inch tires... I graduated HS in 84 so know what you talking about with the "smaller" tires with taller sidewalls but I don't mind 20s in the 275/65 flavor... sure I could run a 35×12.5 and a taller 285/65 or 295/65 but the truck has the stock suspension and don't want any potential rubbing in front. I'm cool with the stock size tires.
What I shake my head at are those 22 inch chrome and up offset wheels with thin profile tires they make now, but it's not my truck nor my money so have at it...
My stock rims are shot. So I was having trouble of finding 17" rims to fit this truck. Was at a parts yard and came across this 08' F250 that came with these 20" rims so I grabbed them for a $1.50 a inch.
But not sure if I like the 20" yet.
I graduated HS in 85 so I know what you are saying about the smaller tires to.
My stock rims are shot. So I was having trouble of finding 17" rims to fit this truck. Was at a parts yard and came across this 08' F250 that came with these 20" rims so I grabbed them for a $1.50 a inch.
But not sure if I like the 20" yet.
I graduated HS in 85 so I know what you are saying about the smaller tires to.
Why not a set of 18 inch factory steel wheels? I run a set with snow tires in winter time on my truck.
I have no idea what year mine were because my buddy who runs a repair shop gave them to me but as long as they are Ford Super Duty steel wheels, they should work. I don't think the lug pattern changed through out the years. No pick and pulls that would have them huh?
