1986 Volvo 740 Turbo does Topic is solved

Guest · Post by **Guest** » 17 May 2005, 23:18

I didn't know how to measure MPG. So what I did was top her up, full tank, & set the trip meter to zero. I then took the miles reading when the fuel needle was midway.

Halfway through the tank, I read 128 miles. So if the tank holds 15.8 US gal. (from the manual), it consumed 7.9 gallons to do 128mi. That is roughly 16.20mpg if my math and logic is correct.

This is rather steep, or is it? Maybe I'm just used to driving Civics all these years, that 16.20mpg is a shame to the 32++ mpg my Honda does. This is my first volvo, and first effort to drive a very cool car (i just love it) that is 19 years old. I just want to know if it is normal for this type/year of car, and if it isn't what is causing it/what do I need to check.

I do not have check engine light on, car runs great 100%, does not have weird sounds, smells, smoke, or anything. Odo reads 188k miles. Car was tuned up about 8-10 months ago, has new Pirellis inflated right, even PASSED smog test in (strict) California 2 weeks ago. So... I really expect it to do ~19/23 like what EPA says. But 16mpg isn't really pleasant when gas in Los Angeles is now $2.79 hehehe...

Thanks guys....

Post by **OrangeAirsoft** » 17 May 2005, 23:42

please remove this post, my newbie mistake, i did not put my username in before i posted. im sooo sorrry... now i have double posts.

Kmaniac in California USA · Post by **Kmaniac in California USA** » 18 May 2005, 21:53

I would like to suggest to you a more acurate method to measure gas milage. You were correct to top off the fuel tank and set the trip odometer to zero. The next step you need to take is, once you need fuel again, top off the tank as before, then divide the number of gallons you add to the tank into the total miles registered on your trip odometer at the time of refueling. This will correct for any fuel gauge error (fuel gauges are not an accurate measurement of the precise volume of fuel remaining in your tank). This method does not take into account any speedometer error. My 1986 740 GLE has a 1 mile in 20 mile odometer error. For every 20 miles of actual distance traveled, my odometer registers 21 miles. I discovered this going through many a speedometer check popular on the California state and interstate highways. The measured 28 miles per gallon I calculated for my Volvo using the above method has been reduced to 27 miles per gallon when the odometer error is corrected. Using the above method, I think you will see a significant difference.

By the way, my 740 is a 2.3 liter four cylinder without turbo. The milage I measured above was all highway, measured on a one day road trip. Around town I get 20 - 22 mpg.

Guest · Post by **Guest** » 19 May 2005, 11:13

that's a great idea to eliminate fuel gauge error. thanks!!!

i will try it again, and post the results. i did not realize the odo can be that off, a mile for every twenty is plenty. i hope there was a long enough straight road with mile markers, so i can find out if my odo is also off by that much.