Thread: MPG question
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Old Sun, January 17th, 2010, 03:23 AM
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Do you guys recalibrate your speedometer when using taller tires?

Reason I as is because with the larger tires you are actually traveling farther than what your speedometer shows, thus lowering your calculated fuel mileage.


Its is surprising how far off they can be. I had changed from the stock 31'' to 33'' , and during a fairly recent road trip(7,800k) I kept a very close eye on actual miles traveled via mile markers, and my trip counter. Now keep in mind I would watch this every day of the trip, and kept a log on it, and it would consistently show that every 10 miles my trip would only count 9 miles. Doesn't sound like much but over a tank of fuel, roughly 350 miles(on the trip), I actually traveled 385. Figure the mileage on 26 gallons, which would show 13.5 mpg, when actually it was closer to 15mpg.


Just an idea........