What’s your MPG with aftermarket wheels?

I had a 19 touring fwd with my 20 inch Asanti inch wheels. Stocks were 17x7.5 (225/65/17) weighing 59lbs vs the 20x8.5 weighing 49lbs (255/45/20).

For the 2 years of ownership and 28k miles I could never get better than 21/22 average mpg and I drove like a grandpa the first year trying to get good MPG.

I recently turned it in for a 21 GTR AWD turbo and first off can I say I wish I went turbo from the beginning. I’d sacrifice a little mpg if I knew I was only going to get 21mpg when it previously claimed 25/31 with the 19 touring.

I swapped my 20s over to my 21 GTR and so far and am getting 20mpg. It claims 22/27 and I’ve read average is usually 22/23. I’m happy with 20 with this GTR being it’s awd / turbo. My first 2 tanks driving mainly hwy and driving mpg conscious I’ve gotten 20mpg thus far.

I wonder if it’s the slight change in wheel size or if this is normal for mpg on both models. I always thought 21 mpg for the 19 fwd touring was too low. Shoulda been 25/26 average IMO.

Guys with aftermarket wheels, what’s your average for your make and model (Location Southern California).
 

Attachments

  • 8BA9C890-375E-44D6-88C4-1214636FF6B4.jpeg
    8BA9C890-375E-44D6-88C4-1214636FF6B4.jpeg
    241.8 KB · Views: 22
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
Your 255/40/20 is actually half an inch smaller in diameter than OE 225/65/17. So, your actual new mileage is even worse...
Main reason is the width of tire from 225 to 255. More friction while coasting.

Weight reduction of wheel/tire helps unsprung weight and stopping distance (width increase also helps here).

I had a BMW 5 (E39) before. It came with 225 rubber. I changed it to a staggered setup (235/255). MPG went down significantly.
 
:
Mazda CX-9 Signature
Tire width and the tire compound are very important factors. If you get the eco low rolling resistant tires, you can squeeze a little bit more.
 
Your 255/40/20 is actually half an inch smaller in diameter than OE 225/65/17. So, your actual new mileage is even worse...
Main reason is the width of tire from 225 to 255. More friction while coasting.

Weight reduction of wheel/tire helps unsprung weight and stopping distance (width increase also helps here).

I had a BMW 5 (E39) before. It came with 225 rubber. I changed it to a staggered setup (235/255). MPG went down significantly.
255/45/20. But this makes sense. Damn sucks. I’d like to get 22 /23 with this new awd and turbo but I guess 20 is what it’s going to be. I did a hwy mpg test recently and yah best I could get was 25 mpg after 15 miles. With the stock 19s got almost 30 same hwy and 15 miles.
oh well I guess the price to pay for the better look
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
I have a 2018 CX-9 Signature. OEM setup was 255/50/20, and my new wheel setup is 285/35/22. New wheels are about 4lbs lighter per corner, tires are Nexen Roadian HP all-seasons. I do have a couple of other mods that may or may not affect fuel economy (Sprint Booster and Corksport air intake).

EPA rates the 2018 CX-9 Signature (AWD) at 20 city, 26 highway, 23 combined. In ideal conditions, my numbers are pretty close, about 25 highway and 22.5 combined. My daily commute is 40-50 km total, with a healthy mix of different speed limits that vary from 50-80 km/hr. As far as driving style, I've never driven with a conscious effort to optimize MPG, even during the few 11+ hour road trips I've made in this car. I enjoy the bit of torque this engine has on a daily basis :)

EDIT: Forgot to mention that I run Castrol Edge 5W30. I'll probably switch to Kirkland Signature 5W30 when my current stock of oil runs out.
 

Latest posts