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what should my gear ratio be for my 295/70/18 on my 2007 f150 4x4? i have an edge evolution programmer and the mm size of tires is 2733. if im correct.
You tires are approimately 34.25" tall or in diameter. That's quite a lot taller than stock. You'd be better off by increasing you gear ratio by the same percentage as the diameter of your tires have increased for best performance. From a 3.73ratio, 4.10's would be close.
Accounting for 3-5% squish (flattening of the tire due to load) the diameter you want to put in the Edge is between 2597-2652.
Start in the middle and then confirm with GPS (instantaneous speed). An even better way to confirm is using the GPS's odometer vs. the truck's odometer over a 10 mile (or greater trip).
And yeah - you need to re-gear (or start saving money for a new transmission).
Guessing your stock tire was around 30" tall. Your new ones are 14% bigger. If you had 3.73 gears then adding 14% would be 4.25. So 4.10 gears would be close. 4.56 gears would be a bit over but would shine towing. MPG would suffer a little.
You're ok with 3.73 if you seldom tow and have 4.6 or 5.4. Doing 4.56 would be awesome for off roading and such. You're getting as good a gas mileage as you can get with what you have in it right now.