Fuel economy thread

[baddabang]

I'm averaging 30.2 mpg currently with mostly highway driving at 60mph. Ecotec ftw.

[Spastik_Roach]

Dads Grand Cherokee: 1996, 4.0l 6 cylinder, 4 speed auto, mostly country driving, driven lightly. Lowest we've gotten it according to the screen inside it (not sure how reliable it is) is about 7 or 8 litres per 100km at around 90-95kph on a long straight piece of road. Town drivings usually around 13l per 100km. Not too bad really.

[jcp123]

Just got back from a 2043 mile trip up to Peoria, IL and back...averaged 32,41mpg (~7.26l/100km)! My best tank was 36,608mpg (~6.43l/100km), which was followed right up with a 35,001mpg (~6.72l/100km). Even when I did some more in-town driving up in Peoria, I never got a tank worse than 30mpg (~7.85l/100km). Brought my lifetime average up to 29.26mpg (~8.03l/100km)

Not bad for a car only rated 28mpg highway under the old EPA measurements and 26mpg highway under the new ones...

[clutch-monkey]

Originally Posted by jcp123

Just got back from a 2043 mile trip up to Peoria, IL and back...averaged 32,41mpg (~7.26l/100km)!

holy crap, nice work
i've been averaging 9L/100km (26mpg) in the mazda lately, not the best

[NSXType-R]

Originally Posted by jcp123

Not bad for a car only rated 28mpg highway under the old EPA measurements and 26mpg highway under the new ones...

What'd you do, draft behind tractor trailers?

What was your secret?

[henk4]

Originally Posted by NSXType-R

What'd you do, draft behind tractor trailers?

What was your secret?

sticking to the speed limits will bring savings unheard of.

[NSXType-R]

Like this?

http://www.youtube.com/watch?v=17lGH1W1l4A

[henk4]

Originally Posted by NSXType-R

Like this?

http://www.youtube.com/watch?v=17lGH1W1l4A

the conclusion at the end is wrong, they were not obeying the law, if you are at the overtake lane you have to overtake.....otherwise you have to stick to the right.

But they must have saved a lot of fuel (even more if they had not been driving there at all, as it was an unnecessary activity to be there).

[RazaBlade]

Have upped my average recently. Was initially getting 47-48mpg in my Yaris, but am now consistently getting 53mpg. My commute has changed route, and I reckon the 10 min section of cruising at a constant speed may be a large factor to it. Will be motorway driving from next month, will report back on how the mpg fares on that!

[jcp123]

Originally Posted by NSXType-R

What'd you do, draft behind tractor trailers?

What was your secret?

No drafting - I can't stand not being able to see what goes on in front of me, although I'd be able to get in excess of 45mpg if I did draft.

Actually, the EPA really got it wrong on the SVT Focus. Pretty much everybody who owns one gets AT LEAST 30mpg on the highway, though there are very few who can exceed 32 with any regularity. Mostly I watched my speed and minimized A/C use. I coast down hills (illegal, supposedly, for whatever reason), or if there are rolling, constant up-down hills like here in East Texas or mid-Missouri, I keep the throttle open the exact same amount, bleeding speed up hills and accelerating down them. Annoys the hell out of other motorists, but they aren't paying for my gas. I also switched to Mobil 1 full synthetic oil, and aired my tires up to 40psi.

I should also add that the above trip was done with a 200lb passenger, and about 250lbs of dog, a cat with 5 kittens, luggage, snacks, dog and cat supplies, etc., and on the return trip I also had a bike strapped to the back of the car which probably killed my aerodynamics. Unloaded, I might have added another 1-2mpg to that...nearly 3200lbs is a lot for a 2-litre 4-banger to schlepp around. I'm also thinking about making a little grille blocker to enhance the aerodynamics, but I'm a bit worried about it in the Texas heat, especially since the temperature's already pretty tightly controlled between 195-202*F as it is...

In-town, I coast up to lights rather than powering through them. Hopefully the light changes before I come to it, thereby conserving my momentum, but even if it doesn't, I haven't used more fuel powering up to it. This has the side benefit of saving a little on brakes, too. I also like to keep my speed up when making a corner, again saving my momentum rather than wasting my speed energy on producing heat with the brakes. I also found a brand of gas that my car seems to get a lot better economy on. That's more or less the basics.

Some of this is because I invested in a ScanGauge II. This is a neat little device that plugs into your diagnostic service port and calculates your instantaneous MPG based on the car's ECU's own measurements. It also can display 16 different pieces of information - coolant temperature, throttle position, intake air temperature, RPM, speed, and more. It also has an OBDII code reader, which is rather handy, and can store and clear codes as well as send commands to the ECU. Using this, you can really see what's going on under the hood (I'm a gauge nut, and Ford's dummy gauges just don't cut it for me) and adjust your driving for best fuel economy. It's $160, but seeing as how the basic code reader I sell costs $70 + tax at AutoZone, I figure the other $90 is what I really spent over and above, and I can recoup the costs in fuel savings in about 6 months.


If the whole fuel economy thing sounds unusual for me, well, I'm making car payments on a car I bought to save gas with, so I'm going to go the whole 9 yards...I don't like half-measures

[Lets Gekiga In]

I'm around 28 mpg in my Saab 9-2X Aero right now.

[my porsche]

Originally Posted by jcp123

Mostly I watched my speed and minimized A/C use.

I read somewhere that a/c use has almost no effect on MPG, however rolling the windows down as a form of a/c severely lowers the MPG.



Well, I have yet to break 13mpg. Something's wrong.


I got 12.99mpg on the tank with about 50% highway driving, and other 5.3L truck and Tahoe owners are saying they get 14-16mpg city pretty regularly, so something's up but I have no idea what...

[Waugh-terfall]

get a hard tonneu cover for the bed? Perhaps that may rid you of some drag?

[my porsche]

Those improve fuel efficiency by about 15% but I use the bed way too much, it would be hugely impractical.

[Bob]

Originally Posted by my porsche

I read somewhere that a/c use has almost no effect on MPG, however rolling the windows down as a form of a/c severely lowers the MPG.

You heard wrong... running the compressor most certainly uses extra fuel, more depending on heat. Effects vary from vehicle to vehicle. It also could possibly raise the engine temp, considering it's probably already hot out if you're using ac, and that can hurt milage more.

Rolling down the windows could have a big effect or a small one, it all depends on the aero characteristics of your specific vehicle.