Mechanics

GASOLINE MILEAGE

2002 Volvo S80

2002 Volvo S80 6 cyl Front Wheel Drive Automatic 80000 miles

When I first bought my used Volvo I would fill up the gas tank with 93 Octane and the electronic gasoline meter would say I can get 585 miles to the tank but in reality with city driving I would get about 425 miles. Then I changed the spark plugs to the Bosch Iridium which cost almost 9dollars a plug and the oil & filter and the air filters and now when I fill it up with 93 Octane it reads 460 miles to the tank and I get much less than the original 400 miles on city streets. I always went to the same gas station and received a reading of 585 but when that changed I went to 2 other gas stations and it remained at 460 miles.

Could it be the spark plugs? Should I stick with original Volvo plugs. I looked at the old plugs I removed and they were really old and worn and had no name branded on them.

Thank you.
Avatar
JohnMartinez
June 18, 2008.



How about we check the fuel milage the old way, fill up record milage drive the tank out refill record milage. Then divide gal into miles see what you get.

Docfixit
Jun 18, 2008.
I did that 2 times after the tune up. This is my 3rd complete fill up and waiting to see the end results. Before the tune up I was getting about 425 miles on the city streets. After the tuneup I was getting about 375 on the same city streets.
Thanks.

Tiny
JohnMartinez
Jun 18, 2008.
Have the computer scaned for codes see if that gives a clue as to what happened.
Let me know

Docfixit
Jun 18, 2008.