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non-fishing truck tire question?
Posted: Wed Oct 20, 2004 8:20 pm
by Jale
Need some advice guys. I currently have 235/15's on my f-150 and was thinking of going up one size to 31" tires.
I have been told that this will seriously reduce my gas mileage(not that it is that great anyway)
Anybody done this and if so what were the results?
If anyone knows of a good deal on some 31" tires it would be greatly appreciated
thanks
Posted: Wed Oct 20, 2004 9:06 pm
by M.T. Livewell
Did it on my old F-150.
No problems at all. Barely even noticed the difference on the tach. Sleep easy, it is a good swap.
Cheap tires ... can't help there.
Posted: Thu Oct 21, 2004 8:00 am
by banjo
On mine, I have 235/75/15s... and I think the 31" tires are 10 and a half wide instead of 7 and a half... so I was told that I'd need new rims to handle the 31" tires. (although someone else said they would go on the same rim... they would just look real fat

) I never did it, so I can't really help you out. Good luck.
Posted: Thu Oct 21, 2004 9:15 am
by big-o
Posted: Thu Oct 21, 2004 10:58 am
by BASSSTALKER
Big-O is right. Also consider your spare. If it is not 31's and your tires are, If you get a flat on the rear, you have to put one of the front tires on the rear and put the spare on the front to avoid burning out any bushings in the diff.
You have a PM....
BASSSTALKER
Bad idea - think twice
Posted: Thu Oct 21, 2004 4:16 pm
by Sportspal
It will reduce your gas mileage, and affect your speedometer and odometer.
You'll also notice some handling difference due to the width of the tire, and you could find some rubbing on the inside when having a tight turn.
You'll also need a full alignment if you change sizes or you'll end up driving on the inside edges until they bald and blow.
The major problem is going to be the tire aspect ratio.
a 23575R15 tire has a diameter of 28.9, and the difference to a 31" tire is that when travelling 100km/hr, you are actually going to be going 107.3km/hr.
Sure, not a big difference, not until you add that you drive 24000km a year.
Therefore your odometer is going to think its actually going 25752km/year.
Its going to make it harder to keep track of oil change intervals, not to even think about what your dealer might say if you ever need warranty work done.
Alot of shops will not even allow you to install tires that are different in size especially on SUV's and Trucks due to a flipping problem. Its their way of avoiding a lawsuit.
Just some words to reflect on.
-Sportspal
ex.Tire and lube technician
Posted: Fri Oct 22, 2004 12:28 pm
by mlamothe
kind of a side topic but i changed the stock 245 75 16's wrangle AP's on our F150 to BF Goodrich all terrain TA KO same tire dimensions. There was no difference in mileage and the noise level was close to the same.
The winter driving was a huge difference, and they also handle just as well if not better in the summer... very happy with them.
Costco was the cheapest price around, also a place near St Laurent.
Mark