OK, I now have about 2000 miles on my auto TSX - up until this tank I WAS getting 28-32 mpg averaging 40 mph (in the city driving home to the burbs on I 35). With my most recent refueling of 93 octane Diamond Shamrock gas, my mpg is now 23 mpg with no change in driving habits or performance of the vehicle. Tank prior was Race Trac (don't know if I should trust their gas, but it was convenient) - anybody have an idea as to wtf happened? Car feels the same, but the gas gauge and trip odometer are telling a different story. Thanks---Brian

 

Any change in the wheather?

 

Not particularly - I little more humid (Dallas), but no cold fronts, etc - just seems very strange to all of the sudden drop 20% in efficiency - tire inflation looks ok (not measured) - I have no clue what happened/is happening.

 

Are you sure there have been no changes in driving? Did you leave your car idling at some point for a long period of time?

 

i'd definitely check out your inflations...not that it would account for all of the change but even a couple lbft(which wouldn't really be noticeable to the eye) could cause a change in economy.

 

Question aboit checking tire pressure.

Can you check pressure at any time, or is it best to do after the cars been sitting, say overnight?

 

You should not check it right after driving, the pressure will read higher as the tires have heated up. You want to wait, at least 3 hours I think. The manual gives a suggestion too I believe.