98 XC BAD fuel mileage, need help

Post by **CIK7** » 13 Dec 2019, 10:18

The engine in my car is fairly immaculate. Intake ports super clean, intake valves shiny, fairly new timing belt kit. I have put in new spark plugs, PCV sys, air filter, all vacuum lines, coolant tank, coolant (2x), complete fuel sys cleaner in tank. Yet my fuel mileage is 14/20 mpg city/hwy. That's what a late 90's Chevy Suburban gets. I understand my V70 has the AWD shaft, but the estimated mpg is 17/26. I called Robert 'DIY' Spinner (RobertDIY on YouTube). He said I should be getting at least 25 on the highway. He said it could be a dirty or broken MAF sensor. There was hair, fabric, and dirt on it. I got it really clean. What else could be affecting my fuel mileage?

Post by **abscate** » 13 Dec 2019, 10:49

Its time for a compression test. If the engine is worn, or valves are leaking, efficiency suffers

Brakes can drag
Get a scanner and read your fuel trims, injection times, assess that stuff
How many miles are on the puppy?

Post by **CIK7** » 13 Dec 2019, 14:20

abscate wrote: 13 Dec 2019, 10:49 Its time for a compression test. If the engine is worn, or valves are leaking, efficiency suffers

Brakes can drag
Get a scanner and read your fuel trims, injection times, assess that stuff
How many miles are on the puppy?

About 145,5xx miles.

Post by **June** » 13 Dec 2019, 15:17

Your car is not rated 17/26 mpg that is for a front wheel drive 2.4L equipped car. Here are some screenshots of the EPA gas mileage for the 2.4 FWD which is not your car and the 2.3 and 2.4 AWD of which one is your car. I owned a new 98 V70 XC 2.3L and it was no gas miser. That was never the point of the car. Also notice Premium fuel is stipulated as used by the EPA during testing. If you use regular and run heavy oil that alone will make the couple mpg difference from what you are getting and what the actual original mpg rating is. June