New Wheels effect on MPG's

[warriormagee]

I'm looking into changing my stock 17's to 22's on my '07 Yukon XL. Currently I'm averaging 21 mpg's. What kind of hit can I expect with my 22's on low profile tires? Any suggested mods for a stock Yukon to help after the upgrade?


Thanks

[HitandRunDriver]

21 mpg... Orly??? what mods are you running at the moment

[Zed 71]

Hybrid?

[My01yuk]

Got to be a Hybrid!

[blueflamed03]

expect less MPG and less brake...

[warriormagee]

As stated in the original post, I am completely stock at the moment. It is a 5.3L engine that will accept Flex fuel, though I haven't used any in it since I bought the truck in March. Also, that was 21 MPG highway. I was told by a co-worker that I could prob expect closer to 15 mpg after changing the wheels. Does this sound right? A 6 MPG decrease sounds excessive.

[blueflamed03]

I bet it's not 'that' drastic. You could always get a Black Bear tune and get more power, and at least 2 MPG of that back :)

[HitandRunDriver]

Not to bash on you but unless you are driving 100% highway and cruising 60-65 with no a/c I don't see how you are managing such high MPG's. A tire of that size will definitely lower your fuel economy and lower the efficiency of your brakes, but not by 6mpg.

[bigblue]

my stock 4.8 got 21mpg stock. Now i got 26s and a Black Bear tune and get 18mpg...but most of my driving is on the interstate at 75mph. Its not going to kill your gas mileage thats bad, maybe 2 or 3 MPG loss even without the tune. I didnt really notice much increase in mpg with the tune. maybe 1mpg better with it.

[Eagle]

Not to bash on you but unless you are driving 100% highway and cruising 60-65 with no a/c I don't see how you are managing such high MPG's. A tire of that size will definitely lower your fuel economy and lower the efficiency of your brakes, but not by 6mpg.

I got a ~3 mpg (corrected) jump when I ditched the 22s for OEM 20s (275). the PO's 22s had slightly over tall tires at 305/45, instead of 305/40. ON the obc it did look like 5-6.

Since you are only on 17s, i'd expect a 4 mpg drop especially when not steady speed flatland driving.

[warriormagee]

Thanks all. I do drive a lot of highway miles, and avg somewhere between
75-80 mph.

[Zed 71]

^ 75-80 mph 07 Yukon XL at 21 mpg... How are you calculating mpgs?

[warriormagee]

Using the MPG display on the dash.

[HitandRunDriver]

Is that instant economy or lifetime economy?

[baron]

Defiantly will go down in MPG's and I'm not sure how much a tune is + all the other little things to do to get closer to "normal," but you always have to think to yourself if there will be sufficient return on your investment (unless you don't really care about that, which, in a truck like this, a lot of people don't).
This is a handy calculator:
http://www.fueleconomy.gov/feg/savemoney.shtml

[warriormagee]

I'm in Southern Arizona, and I re-set the lifetime meter before I take long trips to places like Phoenix or Los Angeles, CA. It's a 3.5 - 4 hour trip to Phoenix, and about 8 hours to where I go in Cali.