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I have an 05 CC and 90% of my driving is highway and has anyone noticed a huge drop in mpg when you put on 22's with 305/45/22 tires? I found a used set and this is what size is on them.

Also any problem with the transmission at all, I have 65k on mine?
 

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I like 'em white
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When i bought the truck the DIC had the avg milage at 15.4 with stock wheels and tires. I put the 22s on about a month after and was around 15.7 after a few thousand miles. Mostly highway driving helps even at 80 im only at 2200ish RPM with my 3.73s. Now im lower because my driving habits have gotten worse but im still in the 15s
 

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Resident Metal Head
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I put 285/40/22's on a few months ago and my gas millage hasn't changed. Still average about 20-21mpg(hand calculated) a tank.
You might have some heavy ass rims or something.

If gas is not really killing you then go ahead with it. But if you bitch about how much gas cost and say you can't put gas in your truck, get some stock 16s.
16's won't fit, he need 17"+ fyi to clear the calipers.

Edit: how much PSI do you have in your tires?
 

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i just switched from my stock 17's back to my 20's w/ 305/55r20 tires and im gettin about 1mpg less.. not to much of a difference.
 

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TROLL REVOLT of 2012
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i remember when i had the 22s on my truck i couldnt really tell the difference.

good driving habits even with rims, you should get good average mpg
 

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Detailer & PC Tech
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I have an 05 CC and 90% of my driving is highway and has anyone noticed a huge drop in mpg when you put on 22's with 305/45/22 tires? I found a used set and this is what size is on them.

Also any problem with the transmission at all, I have 65k on mine?
You might want to try a smaller tire, a 305 is a big ass tire. So you have a heavy tire and assuming a heavy wheel, it will drop.

My scenario, i put 275/45/22 on mine, but mine are also Billet Aluminum wheels and not as heavy as chrome. I've also changed my driving habits tremendously, to the point my fiance tells me you drive slow, what happend to my racecar driver. when my truck had 20"s and i drove it on the weekends only i avg 17.5 with moderate driving. then i put on some heavy 22" and dropped to 17.1, went back down to 20"s and stayed in the 17.2-3 range. then went to 17"s and up to 17.4-5. ever since the 22"s i've been driving much better and i'm at 17.6 as of now. hopefully a tune will help out, and check your PSI often.
 

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U Mirin' Brah?
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cleaning your injectors helps a tiny lil bit. I want to throw on some stock tires, and rims on my truck for a day.:crazy:
 

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Not a
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Before I got a BB tune I got 25 on the highway and about 14 in town (heavy foot). That was also with 275/55/R20's. Now I have 305/40/R22's with a tune and I guess i get about 15 on average (highway+city) :crap:
 

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I have an 05 CC and 90% of my driving is highway and has anyone noticed a huge drop in mpg when you put on 22's with 305/45/22 tires? I found a used set and this is what size is on them.

Also any problem with the transmission at all, I have 65k on mine?
yup. Sucks - Im barely getting 240mpgs compared to over 300
 
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