I've been getting pretty bad mileage lately -- first full winter with my "new" '97 Outback -- and noticed a drop in the mileage (below 20 mpg). I checked the tire pressures and they had dropped about two lbs., I assume because of the lower temps, so I increased it and we'll see what happens. I usually run 30 lbs all the way around.
My mechanic noticed gas in the oil on my last change and attributes it to short trips. Said I should change it at least every three months regardless of mileage. The car uses virtually no oil.
Any thoughts on either of these? I can't think of what would get gas into the oil, and the car runs well and has plenty of power.
I tend to run my tires at 36psi nowadays. However, I've only noticed at best a 1 mpg improvement (if that). I tend to prefer the higher pressure because the tire wears more evenly. Most cars these days have underinflated tires, even by design from the manufacturer.
Sheldon, I would say that it is cold transmission and differential oil partly to blame. That is full time 4wd system and the oil in these systems gets very thick at cold temps. Also the engine does not reach operating temp. as quickly and a cold engine is less efficient. I would suggest a change to all synthetic oils in all systems. This will increase fuel economy and make it easier to start when cold. Sparky
Sheld> I've been getting pretty bad mileage lately -- first full winter with my
Lots of thoughts... none of them will hit the nail on the head but may add up to a partial answer.
Tire pressure: yes, I've played with it over decades and different "generations" of tires. My personal experience is I've settled on generally running my tires about 2 psi over the door sticker for most purposes. It helps fuel economy a LITTLE, but increased tire mileage and handling qualities are the real benefit.
Cold: I don't like cold and don't get moving well when it's cold. My cars are just like me! I don't know how cold your winter weather is, but you may benefit from using the lightest weight fluids recommended in several systems: engine oil, transmission and differential fluids. Whatever applies. If you're already at the lightest weights, synthetics SOMETIMES help cold parts move better, quicker than dinos of the same weight.
Fuel: many areas use "winter blend" fuels that are more volatile blends to start and run easier at low temps. Unfortunately, that extra volatility usually causes them to turn in worse, to MUCH worse, fuel economy. This is especially true if your trips are short or involve a lot of idling. My freeway driving in cooler temps shows little mileage change, but my "round town" driving shows big drops.
Gas in the oil: yes, this is a common problem w/ cold engines and short trips. Though it was probably a bigger problem in the days of carbs, it can still happen w/ injected systems. What happens is you run a richer mixture when it's cold, especially at startup, and some of that extra fuel in the mix can migrate past the rings into the oil. This happens all the time. But in warmer weather, or longer trips, the engine warms the oil enough to evaporate the fuel and it's pulled thru the PCV system and burned off so we never notice it. If your running conditions don't allow a good warmup, then liquid fuel CAN build up in the oil. That's one of the reasons you almost always see "the book" recommending an oil change at "x miles, or every y months." Your mechanic wasn't telling you a story.
Another angle would be to make sure all the usual "maintenance" items like air and fuel filters, plugs, wires, etc. are in good shape. A check of any stored codes, looking for things like weak O2 and other temp-related sensors might reveal something that needs attention, too.
As I said, none of these things is THE answer, but all play their parts. There's good news, though: Spring's coming!
+1 for Rick who covered it all. I will add one thing. Don't let the engine idle more than one minute before driving off. Your car will warm up quicker and use less fuel as a cold idle will be running a richer mixture longer and you're getting 0.0 mpg. Ed
When I was learning to drive, British 4 cylinders were still pretty big in the US, along w/ other European makes. The Japanese were barely here and the engines they brought were similar to the British. VW Bugs (real ones) were pretty big. Most people I knew thought a 2 liter was a BIG four.
The rule I was taught: "If you're going to drive a 4 cylinder under 3000 rpm, turn the ignition to 'off'."
I guess it stuck... except when the engine's cold, I still downshift if it looks like I'm headed below 3 grand!
Now a six is different, an eight way different... :D
Same here: I shift typically at 3,000 or 3,500 rpm. Too many people shift too early, and the poor engines lug. The 4-cyl Subaru is fine with this and is pretty peppy; the 6-cyl Audi really likes it and prefers being shifted at 4,000 rpm and is very easily downshifted.
This won't have anything to do with the dental equipment like sound emanating from the subaru exhaust, would it? I won't mind to keep it up but the toothache soon sets in. I'm slowly buying into that american thing of the "proper exhaust note". Previously I thought it's the rice thing, but now I think the dental drill sound of the engine on my OBS brings out the worst in me. Maybe a moderately loud fart can can drown that a bit. Never needed one before and hope to never need one in the future.
Well, I'm sympathetic here: the Subaru does whine more than the Audi, but I should also disclose that I drive with my hearing aids off, so perhaps I tolerate (or just don't hear! imagine that!) the auditory experiences you unfortunately enjoy. Maybe try an Audi A4?
Depends so much on the engine. I had a TR-6 that would pull like a train from low revs, and if you ride a Harley you don't even have to shift coming into and out of a turn. Torque rules, but you can't seem to get much from a
4 cylinder engine. Then again, sometimes it's nice to rev out a 10 or 12 cylinder engine just for the sweet sound. And if you buy a Ferrari, half the price of the car is the music that comes out of the tail pipe(s).
I have a 1996 Outback with the 2.5 and has any body tried running in only 2 wheel drive and do you know how to do it lots of us around her do it in the summer for better fuel mialage.
"KLS" wrote: > On 16 Jan 2007
10:33:12 -0800, "Body Roll" > wrote: > > >KLS wrote: > >> Same here: I shift typically at 3,000 or 3,500 rpm. Too > many people > >> shift too early, and the poor engines lug. > >
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