Specs vs Actual Fuel Economy for an 2002 Impreza 2.5TS

Hi All,

The specs on my 2002 Impreza 2.5 TS (manual transmission) state the following:

11.1 liters / 100 km (City) - equivalent to 21 MPG 7.8 liters / 100 km (highway) - equivalent to 30 MPG

In theory, I should be able to do 540 KM ( 335 miles) in the city and 770 KM (477 miles) on the highway with a 60 liter tank (15.85 US gallons).

I currently do about 480-500 KM (298 to 310 miles) with about 60% of my driving being city driving. I can't even meet the minimum 335 miles of all city driving.

Car has 38,000 KM so I assume it is broken in. It's my wife's car and she shifts at about 2500 RPMs. She doesn't speed and generally cruises at 110 kph (65 mph). Does anyone have any idea as to why my actual mileage is so different from the specs . Any clues as to what I can do to improve my mileage (other than maintaining tire pressure at recommended levels)?

Thanks

Jim

Reply to
Jimmy
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If you want to match the rated fuel economy numbers, the best way to do it is in a lab, on a test stand. you certainly can't do it in the real world. The numbers are for comparison, from car to car, and are generally unobtainable in the real world.

Incidentally, NRC in Ottawa had some Priuses (or would that be Prii???)...their long term fuel economy numbers weren't a whole lot better than an off-the-lot Echo....which raises the point of why bother?

Reply to
Hallan Blaggit

All my vehicles; Volvos, Saabs and now my 2000 Forester meets both the USA EPA city/highway estimates easily. I don't know about other countries and how they determine mileage. If nothing else it gives you a model to model comparison. ed

Reply to
Edward Hayes

I'm not trying to match the rated numbers. I would just like to know if there is anything I can do to improve my car's fuel economy. Is that ok?

Reply to
Jimmy

"Jimmy" wrote in news:ck432a$bqt$ snipped-for-privacy@dns3.cae.ca:

I have an '03 2.5 TS with manual transmission and regularily get over 400KM on ~45 litres (a typical fill up for me). This is all city driving. I tend to shift between 3000-4000RPM. I've only got 12,000KM on my vehicle. Do you spend a lot of time just sitting in traffic? My commute to work is the opposite of most so I rarely spend much time idling. If not maybe you've got a bad oxygen sensor?

Reply to
Fuzzy Logic

I switched to a higher octane gas. I found that I get much more out of a tankful than with regular gas, and with much better performance. Of course doing so you have to pay more at the pump so overall I'm probably not saving much, if anything.

Reply to
powertrain

One reason is the higher cruise speed. I think the highway rating is for

80 kph. 110 will suck quite a bit more fuel.

Another is cold startup, the car uses quite a bit more fuel until it's warmed up, and that can make quite a difference in city driving, which is typically short hops.

I have an MY02 TS, and expect between 550 and 580 km per tank, normally I fill it when I need about 50-52 litres litres

I have occasionally seen as high as 34 mpg (Imperial gallon that is...) which is fairly close to the rating for highway. I believe I could see

38 mpg if I ever stayed at 80 kph... So, I don't think the ratings are unachievable, just not likely with normal driving practices.

Larry Van Wormer

Reply to
Larry Van Wormer

Agree with previous few posts. Short/cold trips will kill fuel economy. Other than that: try running pressures around 35psi; keep services up to schedule and filters changed regularly; Don't run a/c all the time. Apart from that, it's usually down to how each individual drives - unless there's a fault with the particular car somewhere. Cheers

Reply to
hippo

My '98 Acura Integra also comes close (but not quite) to the rated mileage. So this is why I am wondering why the 2.5TS is not as performant.

Reply to
Jimmy

We've recently moved to the suburbs and I have noticed an small improvement. Can you give a little more detail on the oxygen sensor and its impact on mileage?

Jim

Reply to
Jimmy

I guess the cold weather is the main issue. 35 psi for all four tires?

Reply to
Jimmy

"Jimmy" wrote in news:ck60ar$r8b$ snipped-for-privacy@dns3.cae.ca:

Here is a bit of info:

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Reply to
Fuzzy Logic

I have exceeded the rated milage on the road in real driving. I set the snooze control at 80 k's in the country with little traffic. It can be done

65 mph will not get you high milage 45 to 50 will speed is your trade off to arriving a few minutes later

H
Reply to
Business

Jim, just a thought:- is your math based on the assumption that you're using all 60L of gas? Obviously you won't run your tank dry, and it's possible you're not taking into account the last 5 or so L left in the tank when you fill up and take note of your mileage. FWIW, I have a 2004 2.5 TS 5speed wagon and get about 520 or so km before I feel the little orange light has been on long enough. I think it's designed to come on with about 10L left My driving is about a 50/50 mix of hwy/town, and I don't consciously try to minimise consumption. Just my 2c worth, Chris

Reply to
Chill

Best other way of getting accurate figures is fill up at the same station/pump each time and check actual litres you put in against mileage

- assume that's how youre already doing it. My 99 Outback AT is doing slightly better than that so I'd expect a lighter car to better it everything else being equal. Cheers

Reply to
hippo

You bring up a good point.

I'm usually left with 5L to 8L in the tank when I refuel. If I assume 50/50 (city/hwy) driving, then I should do 650km on a full 60L tank or 590km with

55L of fuel. Since I do about 500km, maybe playing around with the tire pressure and cruising at 80kph might do the trick.

I'll keep better records for the next few weeks to see.

Thanks for the input.

Reply to
Jimmy

i got 38 mpg in my fairly modified 94 impreza 5 speed. go figure

Reply to
A Doc

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