Ways to improve mpg

[mkillio]

I was wondering if there are any ways to improve mpg on your average N/A car. Do performance mods i.e. new exhaust header cold air intake improve it at all? How about porting and polishing the head and intake manifold. Front spoiler, rear diffuser? I tried looking this up but only the increase of handling and horse power were given.

 

[_xxx_]

Theoretically, you could reprogram the motor ECU in a way which will give you lower consumption, but you'll have less power. Some tuners do exactly this.

 

[epicstruggle]

I was wondering if there are any ways to improve mpg on your average N/A car. Do performance mods i.e. new exhaust header cold air intake improve it at all? How about porting and polishing the head and intake manifold. Front spoiler, rear diffuser? I tried looking this up but only the increase of handling and horse power were given.

Here is a great thread on increasing fuel savings. Some are quite easy to accomplish:
http://www.beyond3d.com/forum/showthread.php?t=30518&highlight=miles

 

[mkillio]

Theoretically, you could reprogram the motor ECU in a way which will give you lower consumption, but you'll have less power. Some tuners do exactly this.

Can a local dealer do this or do I need to find a tuner shop?

Is there any mathematical equation for how much weight reduction effects mpg or how hard the engine has to work?

 

[_xxx_]

Sure, there is enough literature about that. Google for engine development/control or such. I'm not an expert regarding mechanics/thermodynamics kind of stuff, unfortunately

 

[ShootMyMonkey]

I was wondering if there are any ways to improve mpg on your average N/A car. Do performance mods i.e. new exhaust header cold air intake improve it at all? How about porting and polishing the head and intake manifold. Front spoiler, rear diffuser? I tried looking this up but only the increase of handling and horse power were given.

Certainly improving the efficiency of your intake and exhaust to remove pumping losses can help your fuel efficiency, but the effect is small overall and depends on your ability not to alter the way you drive as a result of the single-digit increase in power you see. Even otherwise, getting the most efficiency out of those things also includes re-programming afterwards because things like ignition timing and such are all very fidgety, and a minor alteration as a result of mixtures can change your power or efficiency quite dramatically.

Aerodynamic mods like front spoilers, air dams, diffusers are all insignificant, and often make things worse because the increase in weight more than counteracts the piddly aerodynamic benefits. The vast majority of them are all about style over substance.

Most powerful thing I can think of is just getting something to monitor your fuel efficiency as you drive and then just learn from it. There are things like the ScanGauge which plugs into your diagnostic port (usually under the steering column) and can monitor based on actual fuel consumption rate constantly.

 

[nelg]

Over-inflate your tires.
Get a low restriction air filter.
Use synthetic oil, if you have a higher revving engine.
Try some Molyslip E.

 

[OpenGL guy]

Drive slower! On my car, if I'm over ~2500 rpms then the turbo is engaged, which increases power at the expense of fuel consumption. Unfortunately, I'm at around 2800 rpms when I'm driving 75 mph.

Since I've gotten the car, my mpg has improved over time. I started at about 20 mpg and now get 22-23. My old car, which was lower performance, only got 20 mpg.

 

[scooby_dooby]

Can a local dealer do this or do I need to find a tuner shop?

Is there any mathematical equation for how much weight reduction effects mpg or how hard the engine has to work?

You could by an VAFC (air fuel controller) for about $300 which allows you to adjust 16points in your RPM curve, to add or remove fuel. You'll also want a FPR (fuel pressure regulator) so you can lower your overall fuel pressure, they're like $60.

Once you get those installed, you can take it to your local dyno shop, and tune it.

I don't know of any equations re: mileage, but I remember viewing some honda fuel curves and they are "U" shaped, the lowest RPM is not the best mileage, but rather somewhere in the middle, around 2500rpms was the sweet spot in the charts I saw.

 

[Frank]

Depress the gas pedal less and more slowly, and shift upwards faster. Nothing else will even be close to that for improving fuel efficiency.