Poor mileage on 98 Toyota RAV4

Factual Questions
1

I bought a used 98 Toyota RAV4 and I only got 218km off the first tank (cap. approx. 58L (15gal)). What up with that?
Relevant info:

Car has 120,000km
Was checked by mechanic and deemed ok prior to purchase
Most trips are short and engine probably does not reach proper operating temp
This is in a subzero environment (increased rolling resistance due to cold?)
Car is manual transmission and AWD
Power steering pump/belt squeals on startup and lasts ~20 sec. Belt appears to be tensioned well. (I will change belt and fluid to ATF fluid when it gets warmer)
Car is plugged in every night
I avoid excessive idling (I idle it probably 2 mins max before driving)

Is this normal?

(I should add that a parts 2002 RAV4 came with this car (was totaled from side, still drives) and if some longshot part might be defective and is easily replaced, I can do that)

Edited to add:

Car starts and idles normally
Exhaust does not smell rich

2

Here is your answer.

Stop and go kills fuel mileage
Cold start and warm up kills mileage
AWD puts a dent in mileage

3

REally? I understand that those things would hurt gas mileage, but ~9mpg with a 2.0L engine? Huh.

4

Odd.
How short are your trips?
Are they all stop and go?
I have a Ford Taurus that gets 11.5 MPG if I start it up on a cold day and drive the 1.2 miles to my neighborhood barber. There are probably 7 stop signs and I can’t get above 30 MPH at any point.

5

Oh, and at low speeds and holding driving style constant, 90% of your gas mileage differences come from weight. Your engine size is almost completely irrelevant for MPG purposes.

6

I have a 4WD Grand Cherokee and I probably get about 15 miles to the gallon on cold short trips. That’s on a 4L, 6 cylinder engine.

I have a fuel/mileage computer that I check often, so that’s pretty accurate, but then again I live in the country with few stop signs and no traffic lights. I never idle before driving either.

7

A cold day for you and a cold day for the OP have two slightly different meanings. Checking the weather for his town yesterday the high was -12, and it was -20 last night.
Cold start enrichment is huge. It can easily double the amount of fuel injected.

8

Oh, very valid point.
My mid-sized sedan probably gets better overall mileage than the OP’s SUV.
My unstated suspicion is that in an adequately short commute, 9 MPG is neither objectively good nor objectively bad in the OP’s situation.

Still sucks in the subjective sense.

9

There could be an issue with a thermostat opening too soon, or a temp sensor that is reading low, both of which would put a constant enrichment into the car. A plugged air filter could also be a problem.
A competent technician should be able to check these things in just a little while.

10

I don’t think weight is the problem. The curb weight of a '98 RAV4 is ~1200kg. A ‘98 Taurus’ curb weight is 1510kg, according to Wiki.

11

Do summer and winter blend gases make any difference? I notice that even in relatively mild winter temps (32F or so), during the winter I can barely get 300 miles from a full (13 gallon) tank of gas, while in the summer I get 400+ miles, all highway driving. Even now, when it’s about 40-50, I’m hitting half tank at about 150 miles. Or is the difference completely attributable to the reasons you’ve stated? That’s a difference of about 30 mpg vs 23 mpg, and this isn’t in snowy stop-and-go driving situations. Does that sound reasonable to you? I can get as high as 34/5 mpg in the summer on the highway, although 30/1 is more average.

12

I’m told that rear window defrosters use so much power they can noticeably affect fuel economy. Same goes for the A/C.

13

Just chiming in about MPG.

I have an ’06 Pathfinder. I’m was used to getting about 18 + mpg average. Same drive every day. It’s VERY VERY high altitude, two lane mountain highway roads.

This fall, I replaced the OEM BFGoodrich Rugged Trail tires (truly bad, bad tires) with BFG AT KO All terrains. They’re 8 ply fairly aggressive heavy tires.

Between that and the winter blend gas, my MPG went down to 16+ or -.

Since I’m approaching the end of the warrantee, I had a Nissan dealer check out the car. Do a diagnostics.

They said that it was a combo of the tires and winter blend gas.

14

opps. Make that six ply on the tread, and three on the sidewall.

15

That element of my post was in the vein of letting you know that engine size has bollocks to do with fuel economy.

16

The number I’ve seen on forums where folks track this stuff is 10% worse mileage with winterized fuels, even before it gets bitterly cold.

17

Yes, it can make a difference. As Mr. Slant about 10%, more if your fuel is oxygenated. While 7 mpg seems a bit extreme, it is possible. If it were my car, I would do the same things I suggested to Nunavut Boy. Check the air filter, thermostat, and engine coolant temp sensor. If the Air filter is plugged, the car will run rich. If the thermostat opens too early, the car will never get out of warm up mode, and will burn extra gas. If the coolant temp sensor reads low the same thing will happen.

18

I just changed the air filter, but I’ll check out the other stuff. I seem to recall being worried last year in February for the same reason, but my mileage shot back up to normal levels in May or so. We’ll see what happens this year.

19

If the thermostat is failing, wouldn’t that mean the heater would not be throwing off heat? My car’s heater works quite well.

Does the coolant temp sensor run the temp gauge in the instrument cluster? Mine does work if I drive it long enough.

The airfilter was checked by the mechanic before I bought it and he said it looked OK.

Shop rates are horrendous up here and appointments to get your car looked at are hard to come by. I’d rather not take it in if I can help it.

20

Another thing I’d do is switch immediately to synthetic oil. You have a midlife engine, low temps, and stop-and-go driving, and synthetic oil will help in all of these situations - particularly the first two.