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'86 740 Turbo does 16mpg. Normal?

1K views 5 replies 6 participants last post by  oc240 
#1 ·
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....
 
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#2 ·
Re: '86 740 Turbo does 16mpg. Normal? (OrangeAirsoft)

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(from my post at http://forums.swedespeed.com/zerothread?id=38288)

After all this your week end will still have a few minutes remaining to find a long run of highway with mile markers. Under safe and legal conditions set the cruise for 60mph and time the passing mile markers along a level portion of highway. Do many consecutive markers and repeat this in other areas if the wind is up or on hilly terrain. You don't need to use 60mph but it makes the math easier. Before you start this at the first marker write down or remember the trip meter reading to the nearest 0.01 - just guess with your eyeball. At each mile marker note the trip meter and after the last consecutiver marker compare the actual miles driven with the trip meter reading then compute a correction factor to apply to the trip meter which will give actual miles driven. If you were doing 60mph and passed each mile marker at 60 second intervals then you speedometer (not odometer/trip meter) has no error. Any other time means your speedo is off. 58 seconds means your car is going faster than 60mph and 62 seconds means slower but the correction factor is not directly related.

Relax, I'm almost finished.

Now that you have a corrected odo and speedo try calculating MPG over at least ten tank fill-ups starting and ending with a full tank.

Surprise! Your 31mpg went away to be replaced with 17-19 city and 23-26 highway true MPG at best!

Enjoy.

George Dill

Whew!
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#3 ·
well dude, the way i do it is fill up your tank, set your trip odo. and drive it normal till you are empty (dont run out, just go till your light comes on.) this way you can drive normal doing what you would normally do and still calculate your mileage. sometimes fuel gauges dont read exact. (like ever notice the bottom half of your tank goes a litttttle faster than the top?)

once you are empty divide the odo trip number by 15.8 and bam, there you go.
 
#4 ·
Re: (CAscherman)

Quote, originally posted by CAscherman »
once you are empty divide the odo trip number by 15.8 and bam, there you go.
Ill math there, as one wouldn't run all the way down to zero, would they?

Me ... pump it up to first click, and that's it. Same on next fill up, noting the mileage on that receipt. Divide the mileage travelled by the number of gallons it took to get to that first click. That's your mpg.

BTW, California gas sucks. I was getting 25-29mpg hwy on Oregon gas (still 92 octane). I usually see around 23-26mpg hwy here in CA.

-- Kane ... generally feeds the turbo with Chevron or Unocal premium.
 
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