# Tire pressure checked - improved Fuel mileage



## RoBMWED (Aug 3, 2007)

Finally got a dependable, accurate air pressure meter - and checked my tires. My front tires were just at 30psi - and rear tires were at about 37.

Confirmed with manual that 225/40 ZR 18 88W front tires should be at 35psi and 255/35 ZR/18 90W should be at 41psi.

After losing air from left front down to 29psi, the TPM actually activated and warned of low tire pressure. Nice to get that confirmation.

Added the necessary air - refueled - and initial confirmation shows about 4.5 mpg improvement. Actually hit 39.2mpg on interstate only driving for distance of 149 miles yesterday according to OBC.

The ride was more 'jaunty' - but not unbearable by any means.


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## Flyingman (Sep 13, 2009)

RoBMWED said:


> Finally got a dependable, accurate air pressure meter - and checked my tires. My front tires were just at 30psi - and rear tires were at about 37.
> 
> Confirmed with manual that 225/40 ZR 18 88W front tires should be at 35psi and 255/35 ZR/18 90W should be at 41psi.
> 
> ...


Yes, air pressure is crucial for mpg. Still wish I had some actual psi readouts on the computer. Like my Tahoe.

Speaking of which, haven't checked my tire pressure in about two months.:yikes:


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