scoobyster

Yes, I'm very boring
Specifically interested in an Impreza 1.6GL AWD's economy.
Best I've managed is 38MPG on a tank with mostly motorway miles, so I've set myself a 40MPG challenge (I told you I'm boring!)
So what's the most economical way to drive? Obviously, a constant speed is important, but which speed? I seem to remember 56mph as an accepted figure, but I presume it's diferent for every car. I'm hoping for mine it's closer to 70 as I feel a bit silly being the slowest guy on the road! My car (on a flat road) revs at about 2500rpm at 56mph, just over 3000rpm at 70mph.
Cheers,
Scoobyster

Editted to say, I normally get an average of just under 30mpg when I'm just around home etc, and that the official figures for the car say it should get 41mpg extra urban and 32.7 combigned.

[Edited by scoobyster - 3/24/2002 10:11:37 PM]

Alas

Leave it in the garage mate. Probably still have a higher consumption than most cars.
Alasdair

RichiW

LOL


Rich.

Hoppy

You don't buy a Scoob for economy. You buy a Turbo because it's fast. You buy a Sport because... Well, I'm not sure. Because of 4WD?

Edited to add, maximum engine efficency is at peak torque/rpm.

[Edited by Hoppy - 3/25/2002 1:08:55 AM]

hackish

The higher the RPMs the more fuel your car will consume. It will also consume the most where your engine makes peak torque. Something interesting is those people who pop the car out of gear every hill they go down thinking it consumes less fuel. Although marginal this consumes more fuel than allowing engine braking to do its job as the computer turns off fuel and spark for coast downs.

-Michael

Hoppy

hackish, you get most power per £/$ at peak torque.

Cosie Convert

You get most power per £ at peak torque......yes, but the faster the car travels the less efficient it is aerodynamically, also the rolling drag increases with speed.
If you want economy then power per £ does not really figure in the 'big picture' Low speed, high gear, closed loop fueling. Probably around 40 mph 5th gear will be peak on a scoob IMHO

scoobyster

Thanks for that guys, very informative.

Hoppy - No I didn't get my Scoob for fuel economy, but it doesn't mean I don't want any fuel economy
And I'd love a Turbo, but it's hard enough saying "Subaru" and "17 year old" to an insurance company, add "Turbo" to the mix and I think significantly more of them would reply, "NO!".

akshay67

I suppose there's a massive difference in fuel consumption from 2k revs compared to 3k revs than 3k compared to 4k? On a turbo of course - any official figures?

NBW

Most important thing about economy I've found is what's sometimes called 'acceleration sense'. This is basically looking and planning further ahead, so that you avoid braking where possible e.g. on approach to roundabout, if you can see you're not going to be able to pull straight on, lift off early and time your approach so you don't lose momentum.

Reason for this is simple, when you brake you 'double' your fuel consumption - e.g. you already burnt the fuel needed to accelerate up to speed, then you braked, so now you need to burn that same amount of fuel again to get back up to the speed you were doing.

Does seem to make a difference.

Or buy a diesel.

Cheers
Tim

Floyd

iTrader: (9)

You could try the Swedish method (I think). This is where you use 3/4 throttle in each gear to reach 5th as quick as possible and then cruise. The thinking behind this is that the engine is most efficient under high load low revs so this is where you should be on acceleration. You then cruise at 56 miles per hour in top.

Also do the looking ahead and anticipating bit so you don't use the brakes etc.

Have (boring) fun!
F

davyboy

I seem to remember get it on to top gear as quickley as possible using no more that 3000 revs??

56 mph was a stupid guideline, certainly not the most fuel efficient. I remember a mestro dielsel turbo, getting huge MPG figures cos it did 30mph at a test track.

Cant remember too much as I no longer care