Mods to increase gas mileage

[razr_88]

i own a 92 olds 88 royale, and with the recent rise in gas prices, simple maintenance is not enough. i want to increase my mileage with a cheap fix. any ideas?

[curtis73]

No cheap fixes. One thing you might be able to do is have someone burn you a custom chip. The factory left the fuel curve a little rich and the timing curve a touch conservative. You could maximize those two and gain 1-2 mpg, but you'd have to burn 91 octane or better which defeats the purpose.

The cheapest fix would be to trade your car straight up for a Tercel, Civic, or Metro.

The manufacturers of cars have to meet some pretty tough CAFE (corporate average fuel economy) standards, so they've already done about as much as they can with sqeezing the last mile out of each gallon with the 1992 technology they had.

[TheSilentChamber]

Vice grips on the fuel line.


I mean um.. yeah what Curtis said.

[beef_bourito]

if you have a timing light or can get one you can advance the ignition timing a few degrees. advance it in intervals of 2 degrees until you hear knocking, then back off 1 degree until you dont hear it. it won't gain you much but it's a start.

If you want more gains you'll have to spend more money, like curtis said you can tune your ecu or get a new one made. you can get intake, exhaust, ignition upgrades but those are more expensive. ignition can set you back around $150, and it only gets more expensive for the other mods.

[SaabJohan]

Some simple fixes to reduce fuel consumption is

1. Check tire pressure. Higher pressure means a lower friction loss.
2. Car weight. Don't carry around luggage that you don't need. Running without a spare tire might save you some additional fuel but if you get a flat...
3. Drag. Remove all external devices that you doesn't need. Run with the windows closed and so on.
4. Engine and tranmission lubricants. A thinner lubricant will reduce the friction loss so use the thinnest oil specified for your engine. Use a lubricant that is specified as energy conserving, for example ILSAC GF-4.
5. Drive without the A/C and other energy consumers such as electric heaters. This might be dangerous though.
6. Learn how to drive economic; use high gears/loads, avoid unneccasary braking/acceleration, use engine braking.
7. Check spark plugs and general engine condition.

By doing 1-7 you will save more fuel at a lower cost compared to the other ideas mentioned in this thread.

[UncleBob]

you want to get exceptional mileage?

Here's the ticket. (depending on your fabrication ability) its very cheap to setup too!

http://www.utterpower.com/10hp_chevy.htm

[Tonto Kowalski]

Clean or replace your air filter regularly. Or better yet, replace it with a cold air intake.

[curtis73]

Originally Posted by Tonto Kowalski

Clean or replace your air filter regularly. Or better yet, replace it with a cold air intake.

No offense intended, Tonto, but why is this such a widely held notion? Decreasing the temperature of the incoming air raises its density, which forces the computer to inject more fuel. In fact it can have the opposite effect. It can increase power, but it most certainly will also increase fuel consumption.

[beef_bourito]

Originally Posted by UncleBob

you want to get exceptional mileage?

Here's the ticket. (depending on your fabrication ability) its very cheap to setup too!

http://www.utterpower.com/10hp_chevy.htm

That's pretty sweet, if you turbocharged that thing and shoved a bit more fuel in it you could have a nice little off-highway machine, or on highway depending on how much you could get. i wonder how many miles per gallon they get.

[UncleBob]

Originally Posted by beef_bourito

That's pretty sweet, if you turbocharged that thing and shoved a bit more fuel in it you could have a nice little off-highway machine, or on highway depending on how much you could get. i wonder how many miles per gallon they get.

my thoughts also. The bueaty is, the motor is so cheap, maintenance cost would be near $0, and I was also disappointed they didn't list MPG, but I bet its near 100mpg.

The stock 1.0L metro engine gets about 45-50mpg, and has a peak HP of 55. With a high efficiency turbo diesel engine, say 20hp peak, you could probably get at a minimum of 70-80mpg and be "capable" of driving it on the freeway....although you sure ain't passing anyone.

But if you want to talk about serious fuel efficiency....a diesel motorcycle would be the ticket. Kawasaki is making a diesel KLR650 for the military (a on/off road enduro) that gets over 100mpg, but they have yet to make one for the public. I bet they will eventually

[beef_bourito]

I'd say just get a small diesel engine and stick it on some old sportsbike. then get the gearing correct because a 3000rpm engine is not going to use the same gearing as a 12000rpm bike engine.

[UncleBob]

the sport bike thing has been done. They were going for performance though, not focusing on MPG (although I'm sure it was pretty decent....but again, they never mentioned what it was)

They used a European spec TDI 1200cc 3 cylinder out of a VW Lupo. 120HP and 250 ft/lb's at 450 pounds. Would probably be a fun ride.

http://thekneeslider.com/archives/20...-by-star-twin/

[SR Racing]

Originally Posted by curtis73

Decreasing the temperature of the incoming air raises its density, which forces the computer to inject more fuel. In fact it can have the opposite effect. It can increase power, but it most certainly will also increase fuel consumption.

Curtis,

Sorry Incorrect. Yes the increased density will probably make the ECM add more fuel per VOLUME of air. However, you will open the throttle less to achieve the same amout of work. This vastly offsets the injected fuel. The ~14.7 a/f mixture is based upon mass, not volume. And this mass is what makes the HP.

Jim
SR Racing

[UncleBob]

Originally Posted by SR Racing

Curtis,

Sorry Incorrect. Yes the increased density will probably make the ECM add more fuel per VOLUME of air. However, you will open the throttle less to achieve the same amout of work. This vastly offsets the injected fuel. The ~14.7 a/f mixture is based upon mass, not volume. And this mass is what makes the HP.

Jim
SR Racing

unless it improves the efficiency, its pretty mute how much power you have at what throttle opening.

If you want to split hairs, in general, an engine is more likely to have better mileage at higher throttle openings for a given load.....this is one of the reasons small engines typically get better mileage. Although, as with everything involving this complexity....its not that simple. But there's a simple example of why its not necessarily cut and dry

[SaabJohan]

Originally Posted by SR Racing

Curtis,

Sorry Incorrect. Yes the increased density will probably make the ECM add more fuel per VOLUME of air. However, you will open the throttle less to achieve the same amout of work. This vastly offsets the injected fuel. The ~14.7 a/f mixture is based upon mass, not volume. And this mass is what makes the HP.

Jim
SR Racing

The engine must produce a certain amount of power, so if air density increase less throttle will be used. This will increase pumping losses and fuel consumption per produced kW will increase. The difference is most like to be very small though. But during high loads a lower intake temperature will be good.