I recently replaced the stock tires on my factory 15" alloy wheels of my 2006.5 Xb with some P195/60R-15 87T Pirelli Cinturato P3000 85,000 mile tires inflated to 30 PSI, and had the wheels aligned shortly thereafter to the specified range. After replacing the tiresl, I have noticed lower MPG (from 30 to 26 MPG). I'm thinking it may be due to the tires being a little bit wider than the stock P185s or due to the extra long life tread creating more friction... I'm gonna get the alignment checked again soon because the car is still pulling a bit. What do you all think?

 

Put more air in them. 30psi is a little soft. Check your max. Its likely 44 psi, and keep it under that by a few.

I bumped my brides oem tires on the B from 32 to 36 cold and it picked up 4mpg.
New fresh tires (next week) I'll be running closer to 40

It makes a big difference. Didn't you listen to noboma?

 

adding to that, 195/60 are slightly bigger tires than the 185/60, so your odometer is reading slower than before. (go here if you need exact numbers: http://www.1010tires.com/TireSizeCalculator.asp )

have it checked to correct the pulling, but definitely pump those tires up at least to 36 psi and above. anything passed 38-40 will affect your ride quality

 

im running 195/60-15 on the stock steelies and i keep mine pumped at 44psi

 

Def. air them up to like 37-38 psi. Plus you have to remember your speedo is more accurate now.

 

I just had the same issue, was gettin 30-33mpg switched to 195/60r-15 on my 15x7" wheels and my first tank was 25mpg kinda mad. Then I air them up to 36psi (was 30) and am now gettin 30mpg again on my last 3 tanks. I may have made an error on my first tank tho, dont know.

 

Oh and btw my tires are Falken 512s Ziex, nice and they stick good but have good tead wear. My factory Goodyears were pretty much done at 22k miles.

 

I am running kumo 195/60/15 stretched tires and still get 30-33MPG. I just have to pay attention to the speed limit.

 

When you calculate your mpg, multiply the miles on your odo by 1.02.

I am running 195/60/15 Kumhos @45psi, and I just had a 39mpg tank, combined with blocking off the bottom grille and driving very gently (I spend a lot of time rolling in neutral in town).

 

running same size and I get about the same going very fast a lot of the time