Today after spending $40 to fill tank I kept wondering why RWD volvo's have such a low mileage. To be precise, today fill up shows 18.2 gallon for 400 miles. This a little bit more than 22 miles per gallon with 80% highway driving. When the car is mostly driven by my gf who did 80% city driving, the gas mileage is around 17mpg.

I searched old posts and found my mileage is kinda normal. Maybe on the low normal range but still normal. Now comparing to my other cars, it is really low. My 1990 Acura Legend has roughly the same weight with the non-turbo 944 and has a 2.7L 160HP v6 engine . The gas mileage on freeway is 26mpg. My 1989 Toyota Supra non-turbo weighs almost 400 pounds more than the 1994 944, with a 3.0L 200HP I6 engine. The gas mileage on freeway is 25mpg. The Legend may have less power loss as a FWD car. But the Supra is also RWD, with significantly more weight, and almost twice the horse power, yet it still gets better gas mileage.

I am really confused. Such a low gas mileage really hurts with today's gas price.
--
1994 944NA 100K miles

With the 940SE turbo wagon I'm getting around 21MPG (93 octane) mostly highway and maybe 20% city driving. The lack of a lock up torque converter hurts bigtime on the highway. As stated in some of the other posts speed certainly plays a big part in MPG. Most of the trip is at 70 plus, which doesn't help mileage as well as having to run the AC all the time. Staying out of turbo territory is also very helpful, but there are occasions where I do have my fun. With the mileage I am getting now I don't have any complaints.



91 940SE sedan and wagon, 300M

Despite the gasguzzler reputation, if you compare our less than spring chicken cars with others of a similar weight, they are really much the same.
I was browsing on the edmunds site for gas economical cars, even the new midsize ones are really not much better.

Dan

I recently drove about 300 highway miles round trip doing about 60 MPH. According to my handy dandy little gas mileage slide rule, my gas mileage was 31 MPG. Yes, 60 MPH is kinda pokey but I think it gave me better mileage than I would have if I went faster.

My mileage in normal city driving is about 26 MPG. I use 93 octane gas - not sure if that makes a difference but I doubt it.
--
Mike F - 1984 244 DL - 244,000 miles - Undergoing reconstructive surgery with POR-15

It seems the brick shape and the design of the engine have a lot to do with the low fuel efficiency. It's great to learn something everyday
--
1994 944NA 100K miles

Try a tune-up and air filter. Go max press on tires as stated.
When I was driving my 940 alot I got 27 mpg intersate. I now have a s80 I get 30 mpg on interstate and about 27 combined @ about 25% city 75% interstate.
Its hard to go by HP. The new corvette is about 400 hp? and it gets like 26 mph. I also have a 850 bmw, 12 cyc. car and you would think it leaks fuel its so bad. I don`t drive it much though.

Lane

Lots of factors affect mileage. My 87 745T automatic got at the best of 26 - 26.5 at 65 mph. I swapped in a M46 and changed the rear end to a 3.31 and filled with synthetic oils. Went to a 16 inch tire and always run 36 psi all the way around. Lowered it to cut down the air flow under the car. All the changes increased my gas mileage to high 29's low 30 mpg. I have seen a very occasional 31 mpg at 65 mph. A non turbo 900 should be running in the 29 to 31 mpg range on the highway from input of other people I know that drive them.
Lets face it these rwd cars run between .42 (240) to .36 (late 960) Cd's.
Other factor with Volvo's is the torque range. A lot of other automobile engines are making more torque at lower rpms so they don't need to be geared as low as a Volvo. Ever wonder why a Corvette is rated at 28 mph highway? The car only needs to run 1200 rpms at 60 mph. With the changes in my car I dropped my RPMs almost 150 rpms. Just for an example in 4th at 2000 rpms I'm running 45 mph. At 2500 rpm in OD I'm running between 72 and 73 mph. Before the changes 2500 rpms in OD would have got me 65 mph.
The easiest and cheapest things to do in order of cost is fill the motor, transmission and rear end with synthetic oils. Synthetic in the motor will give you the least improvement with synthetic in the differential giving you the most. Increase the gearing of your differential. If your car came with 3.90's then drop to 3.73's. If it came with 3.73's then go to 3.54 gearing. Do not drop more than ONE level. If your transmission doesn't have a locking torque converter then find one with a locking torque converter.

I can get around 27 mpg on a trip in the 745, but my wife gets around 25. Different driving habits make a diference. ANd notice I say habits, things you do unconciously. On a trip out west several years ago we rented a Ford 9 seat van with a 469 engine. When I drove we got 16mpg, when my friend drove we got 14.
The fellow I bought my 745 from got 30mpg, I have gotten that once. But on the highway I go 75, maybe he obeyed the limit and was at 65.
SPeed and technique make a lot of difference.
--
744 & 745 16v 4+OD, 245 SE auto, 242Ti 4+OD, 245DL auto parts car

As mentioned, the "brick" shape and the older engine technology.

Also as previously suggested, remove all extra weight. Go light on gas pedal. Tires at or near 36 PSI.

Make sure properly tuned with a clean air filter being particularly essential!

Might try synthetic engine, tranny and differential oil for reduced friction....

--
90 244DL 252K - original engine/drivetrain :)

Simple answer. The 900 sedan has a CD of .38. We don't call them bricks for nothing. Anything above 70mph will murder fuel economy. Even an old honda/acura from the early 90s will have a CD of .33 or less.
The engine design is not conducive to efficiency. The B230 M cam is set up with wide lobe separation. This yields good low end torque at the expense of fuel economy. Lets face it, this is a tractor motor (a very good one at that).
When the engine computer encounters high load such as acceleration and highway situations, it doesn't take much for it to switch from closed loop operation where the O2 sensor accurately governs air fuel ratio (at~14.7:1) to open loop where the AMM does all the measuring based on fuel maps (at 13:1 or less). To put it bluntly, LH2.4 sucks. Some of the people that have built their own megasqirt engine management system on highly modified B230FT engines are reporting fuel economy of 25MPG+.
This is one of the open secrets in the automotive industry. All fuel economy and emissions testing is done at low engine load. As soon as the throttle goes past 60% (or there about) engine computer ignores the O2 sensor, pours on the coals and HC emissions go through the roof. The government turns a blind eye to this as long as the public is happy because they drive a SULEV accord. They have threatened to add a full throttle high load test to the future EPA standards but nothing has come of it.
Unless you are the stereotypically ultra conservative Volvo driver, fuel economy will suffer.
We have a 89 244 and a 94 965. The 960 consistently gets equal or better fuel economy than the 240.
960: 21-25mpg
240: 19-22mpg
All on 87 gas with same driver on the same roads. Go figure.

Justin
Who is still tying to master the water in the basement.

When the engine computer encounters high load such as acceleration and highway situations, it doesn't take much for it to switch from closed loop operation where the O2 sensor accurately governs air fuel ratio (at~14.7:1) to open loop where the AMM does all the measuring based on fuel maps (at 13:1 or less). To put it bluntly, LH2.4 sucks.

Is this open loop mode considered unusual as per industry?

Maybe a lower stoich (richer) is better ... certainly I'd always want to run my car erring on the rich side.

If you say LH 2.4 sucks, what would you consider a better Volvo system.
--
Norm Cook Vancouver BC; 1989 745T 204,000KM

40 dollars to fill your tank ?, thats £22 , you yanks make me laugh, i put £50 in my 960 thats 90 something dollars and it aint quiet full, jeeze if lived over there i`d be riding round in a blown 10ltr hemi.

Yes, we are spoiled brats here in the US when it comes to gas prices. People don't realize how little gas prices have risen over the years compared to the rate of inflation.

Personally, I'm laughing at the SUV people whining about gas prices.
--
Mike F - 1984 244 DL - 244,000 miles - Undergoing reconstructive surgery with POR-15

Gasoline in the US is a bargain. Cheaper than beer, milk or bottled water. Of course the long term costs of fossil fuel usage are not being adequately addressed. And the real short term costs are being hidden by various government 'adventures' that amount to taxpayer subsidization of the oil co.'s, and insure their record profits.
--
Gary Gilliam Sumerduck VA, '94 940 na Regina 150k, '86 240 180k

Your mileage seems a bit low compared with some of the others of same vintage. I'm sure I've seen folks report back mileages of 28 for 100% highway.

With respect to other mileage vs your other vehicles, aerodynamics + engine design are contributors, IMO. Your car would have the lockup trans so that's helping out.

But I've noticed my B230 is a giant heater. Even though my '89 745t is very efficient (with respect to emissions), it produces a tremendous amount of heat during normal driving in moderate ambient temps. What this tells me is I am losing energy to heat loss instead of motion.

As a comparison my Honda does not produce anywhere near as much heat. I am taking into consideration driving habits, distances, ambient temps, engine size to weight (how hard the engine is working) etc. It's anecdotal but I also cannot figure out why my Volvo, when driven very carefully, gets such bland gas mileage.
--
Norm Cook; Vancouver BC; 1989 745T 206,000KM

See my sig. - same car. City driving in deep winter gives me 17-18MPG (US Gal.) I routinely get 28-30 on the highway at about 70MPH. I've corrected for (slight) odometer error. Lightweight synthetic engine oil, fresh plugs and air filter, O2 sensor tested and functioning to spec, tires at 35psi and a recent wheel alignment do it for me. Car has 162k mi.
--
Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar 77 MGB, and a few old motorcycles)

I think you mean "Why is my car such a gas guzzler?".
Both of my 700s get ~20 around town; the manual gets 27@75MPH, the auto gets 25.

the engine design is antique. Emissions gear + gearing + 1000 other factors affect it.

My 1954 Ford has a 3.7L 223 cubic inch inline 6 cylinder and gets 20 mpg WITHOUT overdrive (3 speed manual)

The models with the overdrive could get 25 mpg. This is a car that puts out more horsepower, a lot more torque than a 94 Volvo, and it's 40 years older technology. The lack of any sort of emissions equipment is mostly to blame though.

It just varies greatly. My 1998 Beetle TDI is getting around 50 mpg now that summer weather is here. I bought it and got rid of my Volvos. However, I just bought my 960 because it gets twice the fuel mileage of my F150, which gets about 12 mpg in town.

But I guess this is why I show up to work every day.. Gotta make the $$$ :)
--
'92 965

I tend to think the old technology contributes a lot to the low gas mileage. But after reading volvodad and mcduck's reply I start wonder what else needs to be done on my car. Since last October I bought the car, it has
-new distributor caps, rotors,
-NGK spark plugs,
-new flam trap, air filters
-new Bosch O2 sensor,
-new bushings, ball joints,
-tires always 32-35psi,
-oil change every 3 months (which is only 1500 miles , but I changed it anyway for most driving are in town),
-89 octane gas from either Shell or Sunoco

I did not clean the ICV and throttle body, but I think that should not hurt the mpg? The only thing left (I think) that may affect the gas mileage is spark wires. But can they hurt the gas mileage by 5mpg?
--
1994 944NA 100K miles

I just got back from a 700+ mile round trip,94 940 loaded with stuff , two people + dog with the air conditioning on half of the time, and averaged 27.5mpg. One of the tankfulls was close to 30mpg straight hwy cruising, and the other was around 25mpg mixed hwy with heavy stop and go traffic through lots of stop lights and then freeway snarls. I regularly clock 25+mpg ( averaged over 5 tankfulls) in mixed suburban/exurban driving. When my 23 year old son uses the car, it drops to 20-22mpg or less. The input from the driver, no jack rabbit starts with gradual speed changes and hold speed under 70mph (if possible), is one of the biggest factors determining mpg.
There are a few other things you can do and/or check to increase mpg.
Jack up each wheel and check for binding brakes, or bad/incorrectly adjusted bearings. Change the fluid in the differential and replace with Mobil 1 synthetic ( or another brand) gear lube. Check for proper resistance on ECU coolant temp sensor. Go ahead and clean the t-body and IAC. Make sure the tires are up to 35/36 psi. No extra weight ( trunk full of old books,mother-in-law etc) in car. No excessive idling, like long morning warm-ups or leaving car running w/ac on while in store. If it is at 100k, when was the last timing belt change? Slightly retarded valve timing from a stretched belt will surely drop power and mpg.
--
Gary Gilliam Sumerduck VA, '94 940 na Regina 150k, '86 240 180k

No excessive idling, like long morning warm-ups or leaving car running w/ac on while in store.

In this town, leavng a car idling while in the Stop-n-Go will mean you walk home. Your car will be either stripped or in Mexico by nightfall.

I use two keys. One in car, with a/c running, the other to unlock it when back from store.

Good Luck,

Bob

:>)

I dunno... I'm pleased with the mileage I get with my 1992 940. I drive 45 miles each way to work... easy highway miles... probably averaging 65 mph. I've checked my mileage numerous times (hey... it's a fairly "new" car and I'm curious!!) and it's never under 30, with a high of around 32. The worst I've gotten (combination city and highway) has been around 27, give or take 1. I believe my odometer is accurate (at least, according to measurements between highway mileage markers)and I'm as careful as I can possibly be when I fill the tank to make sure I'm getting as close as possible to the max fill level. If the cars are in proper tune, I'm confused as to why there would be such a discrepancy. I must say though, as I get older, I certainly don't stand on the "loud pedal" very much. That might help.

Steve

My wife averages 25mpg in our 111,000 mile '95 855t. She does this hauling two kids around doing errands and running into town, 20 miles, a couple of days a week. I manage 22 if I use it for my 30 mile mixed commute daily.

My 198,000 mile '88 745t w/ M46 & OD, which I drive exclusively, manages 22mpg on my commute. Same as the 855t. As an experiment with the 745t, I followed the shift light for one full tank of gas and managed 22 mpg. For the next tank I lead-footed it running to 4500 rpm regularly before shifts to 3rd & 4th, quick starts etc. I managed to get 22 mpg from that tank too.

Fresh plugs, filters, cap and rotor.

Go figure.

We do complain about fuel prices here in the US but at $3 per gallon we'd still have it good compared to the UK & Europe.

Erwin