I just purchased a 2004 V70 2.5 T with 138K miles
And drove it from Conn to Indiana 852 miles
Got 31 MPG
Just replaced a super dirty air filter ( Napa) and cleaned
the mass air flow sensor.
Just drove 100 miles on the Interstate
and got only 22 mpg
What the heck did I do wrong?
Jeff

 

Did you use a product like CRC MAF cleaner or a generic carb cleaner on the MAF? some carb cleaners are too harsh and can damage the MAF. Another possibility is you got a tank of gas with a lot of ethanol. See if runnning a tank or two of brand name premium gas helps. After that I'd be checking to see if you have an intake air leak which may be throwing off the mixture.

 

I've never seen 31 mpg from our V70T, even on Interstate at moderate (70 mph) speeds. Best I can remember is 24 mpg.

I know that doesn't sound very good, but it's just a fact.

My ancient Caddy Fleetwood, 4400#, LT1 350 ci will do 22 all day long. With 4 passengers and a trunk full of luggage.

But my wife loves her Volvo, so who cares about a few mpg? She won't trade her Volvo, and I won't trade her.