Manual vs auto fuel economy

SomeGuy537 · Post by **SomeGuy537** » 23 Jan 2022, 10:27

Hello people! I'm considering buying an 850 with a manual trans in hopes of getting better gas mileage. I have a VW Golf right now (which i'm not terribly happy with). I was forced to sell my lovely well equipped 850 GLT auto because of the dreadful fuel economy which was around 19-22 mpg combined. Now i'm curious about what numbers you guys are getting. Please specify what type of driving you do aswell as what engine you have too. In my experience older cars are a great deal more economical with manual transmissions than autos so it would be interesting to see how big the difference are when it comes to 850's.

Post by **Clemens** » 23 Jan 2022, 15:03

My 850 10V with AT used around 10 Litres/ 100km, my 96 R (AT) and 94 T5 (Manual) use about 11-12 Litres/100 km quite equally, depending on the amount of city and freeway driving. The difference here is mainly my gas input. The 10V with AT was the most economic of the three, because it was lacking 100hp.

Post by **scot850** » 23 Jan 2022, 17:05

What gallon are you using? UK or US (4.5l or 3.8l for the gallon calculation).

When I had a 850 AT (1993 GLT with the 20V engine) with some city driving and country driving it would regularly give 28 mpg (UK). On a run outside the city it would go into the mid 30's on the Highway (UK gallon).

My 98 V70XC AWD AT with a 4 speed auto would get up to 38-40 mpg (UK) on the highway but mid 20's in town.

My 2000 V70 NA with the 5 speed auto my buddy bought from me he has seen 7-7.5l/100km on a highway run but 10-11/100km around town.

My 2000 V70R (5 speed auto) is dreadful, but rarely gets a decent run other than around town. On a good day maybe 20mpg (UK) and on the highway 28 mpg (UK).

Neil.

Post by **FireFox31** » 23 Jan 2022, 19:50

I owned a 2000 V70 NA manual for 18 years and now have owned a 2000 V70 NA automatic for the past year. In 2016-2017, my manual got 26.0 mpg city / 27.1 mpg highway, typically carrying me and 50 lbs, with maybe 245-270k miles. In 2021, my automatic got 22.4 mpg city / 24.9 mpg highway, typically carrying me and 350 lbs, with 205-215k miles. These are calculated from gas receipts averaging summer and winter gas, using US gallons.

Maintenance of the car may help improve fuel economy. Stuck airbox flap, dragging parking brake shoes, worn spark plugs, and many other things can eat away at mpg. I've been working to get my automatic to stage zero, though have yet to see a drastic improvement in mpg from any one maintenance I've completed. My manual was not in impeccable condition, but I think the automatic must have some problem which the manual didn't.

Weight you're carrying will also affect fuel economy. Because I'm rehabilitating my automatic at a local shared-access garage, I've been hauling around all of my tools and many parts all year. That's why I noted the estimated carrying weights above.

Ultimately, get a manual. They're way more fun. And do everything you can to bring its maintenance to as-new, stage zero condition so you get the best mileage.

Post by **hausmeister** » 02 Feb 2022, 05:17

Check https://www.spritmonitor.de/en/ for lots of different datapoints.
But, I don't think you will be able to drive an 850 below 9.5 to 10L /100km realistically. That is about what my 10v manual s70 used and it was always well maintained. For my T5-R AT it's about 11.5L - when you consider it has about double the hp I'd say it is way more efficient.
The lowest I ever managed on the s70 was ~7L when going consistent ~100kmh over very long distances.

When fuel efficiency is a priority, I'd not get any 5 cylinder volvo, except maybe a diesel.

Post by **abscate** » 02 Feb 2022, 05:23

Our 1999 NAs will get 30 mpg or about 8 liters per 100km on Highway at 110kmh/ 62 mph

On the Highway , if you keep the converter locked up with a light foot you should even do better with an automatic..I think the final drive is lower? Unlocked, economy will suffer of course

befarrer · Post by **befarrer** » 02 Feb 2022, 16:27

I'm lucky if I see under 10L/100Km on the highway, but I have a LPT, auto, and AWD.

shegarty · Post by **shegarty** » 04 Feb 2022, 12:06

abscate wrote: ↑02 Feb 2022, 05:23 Our 1999 NAs will get 30 mpg or about 8 liters per 100km on Highway at 110kmh/ 62 mph

+1 on this - my 98 S70 T5 averages 8.2-8.5 l/100km in warmer weather and just over 9l/100km in winter (and that is here in Canada with extreme temps and snow covered roads). Keep them well tuned and with a light foot they get pretty good gas mileage.

Post by **hausmeister** » 04 Feb 2022, 12:15

+1 on this - my 98 S70 T5 averages 8.2-8.5 l/100km in warmer weather and just over 9l/100km in winter

Depends on driving conditions, if you really have long distances where you can drive consistent speeds then the fuel economy is ok.
I am used to comparing a whole tank fillup for fuel usage.

befarrer · Post by **befarrer** » 05 Feb 2022, 12:12

I find anything that causes boost, your fuel mileage drops. I get much worse city driving than highway, from accelerating. I also pulled a 6' x 6' trailer with a snowmobile 300km on the highway, I got 14l/100 km, the extra drag killed my fuel mileage.