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Bigger wheels/tires and MPG

chad202

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Went from 20x9 stocks wheels with 275/55 tires to 22x10 with 305/45 tires and MPG dropped 1.5-2 MPG. Guess everything good still has downfalls. lol I knew it would drop, just hoping it wouldn't. You could definitely feel the added weight. Even with just releasing the brake pedal the truck doesn't roll as quick as it used to and throttle input not as responsive. Maybe once I lower the truck a couple inches and add toneau cover I'll get the MPG.
 

LuckyWelds

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So you went with a slightly shorter and wider tire so you're making more revolutions per mile with a higher coefficient of friction than you had previously.
Are you basing your averages off the dash or are you calculating it at the pump?
Did you have your speedo adjusted after? It won't be a lot but you'll be a few mph lower than what your speedo is reading with these tires.

You might recover a few mpgs with the lowering and tonneau, I'd be interested to see if you balance out.
Definitely get your speedo adjusted as you'll be clocking more mileage than you're actually putting on.

Also, you can always adjust your differential gearing to get your responsiveness and drivability back.
 

chad202

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A 305 tire is bigger and wider than a 275 and one is a 20" and new one a 22". 275 is 31.9/10.9". This new 305 is 32.7/12". I didn't get the speed odometer adjusted cause before it was off 1mph on the low side of what speed odometer showed. Now it maybe slightly higher than what speed odometer shows but only like .3ish
 

chad202

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19Jake, I have your brother from another mother. 3.jpg
 

LuckyWelds

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A 305 tire is bigger and wider than a 275 and one is a 20" and new one a 22". 275 is 31.9/10.9". This new 305 is 32.7/12". I didn't get the speed odometer adjusted cause before it was off 1mph on the low side of what speed odometer showed. Now it maybe slightly higher than what speed odometer shows but only like .3ish

275/55 = 31.96" Tall 10.8" wide
305/45 = 30.8" Tall 12" wide

at 50mph you'll be reading about 1.5 mph faster than you're going on the 305 than you were on the 275
 

Lize

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throttle input not as responsive
I've been wondering about size increases as I see so many people doing them but not commenting on throttle response so its interesting that you note a difference. I've only experience of one truck with larger tyres and those were hugely bigger than stock and so unsurprisingly were a very noticeable power drain.

Have a look here:
Unless I've put something in wrongly (which is quite possible!) it looks like your speedo will be reading lower with the new wheels?

22506
 

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