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Volvo S80 around town Fuel economy.

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3.2 fwd mpg s80
3.3K views 5 replies 6 participants last post by  stupid_nut  
#1 ·
My 2008 3.2 FWD S80 seems to have questionable fuel economy around town, although I'm not sure if it is because I live in a small town and rarely go on the freeway, or if something could be wrong with the car. I just moved into the city center and have a short commute but pretty much everywhere I go is start and stop start and stop at every intersection either at stop signs or lights. Santa Barbara is basically a grid with very few long sequences. Typically, my computer says that my average speed is about 9-10 mph and the my mpg is about 11. I can't seem to get it to rise no matter how lightly I drive. Though, when I go on the freeway, these speeds seems to produce expected results at about 25-27 mpg. I know I really am pushing the definition of "city" with all the stop signs, but should the car ever get that low mileage? with gas at 5.70 a gallon, it pains me to think about how much I spend on gas each day...

At the same time I moved, I did the drive belt and pulleys etc and just got4 brand new all season tires. Car has 90,000 miles.
 
#2 · (Edited)
I am resigned to 16 mpg in my town which is disappointing, but normal. I do get much better on the highway like you. Combined city/highway driving is rated at 18 mpg using premium gas for our cars. So, city-only driving is going to be much less. 11 mpg is especially low and might be attributed to your route and driving habits. I would have everything checked out on VIDA or OBD II diagnostics. Try a different premium gas and get good tires and keep them at optimal pressure. If you have 4C transmission, use Comfort mode and never Advanced mode.
 
#3 ·
Yeah. That's abnormally low for the 3.2. I know these are heavy cars and all but sheesh! I have the heavier XC70 3.2 and I'd say I average around 18-20 city and maybe around 24 highway (gotten as much as 26 on a good day). I remember the manual saying something like the car being able to take Regular 87, but for optimum fuel economy and performance to use Premium. I've done tests with both and yup. While I can't tell much difference with power, I DO notice a pretty decent difference in MPG. I definitely take a few miles per gallon hit when using regular, so I stick with premium now. Also, x2 what blindkarma said above about your tire pressure. Check that for sure.

Also check air filter and replace if dirty - I typically use Volvo's, Mann, and Mahle. All good. Went with a few random ones from auto parts chain stores and they seemed noticeably worse so I swapped them back out. Don't know if it was just placebo or something else though. Haha.

Lastly, at 90K, you could be coming up on spark plugs so might as well swap 'em out if they haven't been done. EASY job on the 3.2. I've stuck with Volvo branded plugs and they've served me well. Cheap enough for a 6-pack at FCP Euro but make sure you match up to your vehicle to ensure you're getting the correct ones as they're pre-gapped and all. I don't wait til the 100K. They're SO easy that I just do them about every 50K and it seems to restore some pep and maybe a mile or 2 per gallon. Especially this last round when I swapped out all the coil packs (again) to go with the fresh plugs.
 
#4 ·
That is too low for the 3.2. My V8 shows about 14-15 mpg in town. Air pressure in the tires ok?
 
#5 ·
If your average speed is low, and you're doing a lot of low speed stop and go, 11 wouldn't be too far out of question for what the computers thinks you're getting. That being said, have you done it the old fashion way, where you calculate miles divided by gallons to get your actual mpg? Car computers aren't ever really accurate, and at low speeds it might be getting skewed more than it should