Well i grabbed a set of 20" boss rims and put them on my 99 s10 for the summer and i wasnt really paying much attention to the gas consuption. I normaly put in 40 bucks a time when i fill up and this week i got 215km for 31-32L which equates to about 19mpg. Doesnt sound to bad for the truck but just sounds off and i know my buddy with same truck and also heavy 20s was pullin about 400kms/55-60l tank when i was doing 500-550km on stock 16s at the time. He couldnt figure out why his was so much worse on fuel then mine was but i guess now it makes sence...

I realize the 20s weight alot more then stock 16s and is this my isssue that they are affecting my mileage or are the 20s screwing with the odometer and making it read slower? I know last year when gas around 1.05L i was putting in 40$ and getting roughly 350-400km. Yes i know gas has gone up 30c since then but just doesnt sound right and im ready to swap the 16s back on to compare and if much better ill sell the 20s and put the rest of coin back into the bird.

Thoughts?

What is the tire diameter? That will tell you if it is affecting the speedo/odometer. Any rotating mass will affect mileage more than having extra weight in the back.

245 or 255/35 20s... If it was a toy I wouldn't care but being my dd I'd rather put the extra 50-100km back in my tank then have bling and shit ride quality.

They are larger diameter so your speedo/odo is off

Where'd u get the rims from man? Have pics??

Don't have any pics but there Boss 304s.

Going to throw em on kijiji and see what happens.

Thinkin about picking up another set of 3rd gen 15" iroc rims with summers. They were lighter then my stock 16s I sold to get the 20s and the rubber is a lot cheaper to replace.

The C5 wheels that I sold is a lot lighter than IROC wheels