I've seen on several posts and many websites that certain performance parts can improve gas milage:
- Underdrive Pulleys
- MDS ignition
- HI Flow CAT
- Exhaust
- CAI
- Tire Pressure
- Grounding System
- Light weight oil (0w-30)
- motorsilk (a one time use additive that reduces engine ware).

Are these things for real or just another way to make people money during their attempt to improve MPG.

 

i think their mainly just for performance, performance is meant to give u more hp i dont think its really going to save u any gas, but i could be wrong... from what i heard cai will save u some gas... but not 2 much

 

That's what i was thinking, but grounding system website claim 12.45% in MPG; magnaflow claims improved MPG with their CAT and exhaust. I know about the tire pressure part, but wouldn't there be some kind of limit? I know small increase in HP can give you a little better
MPG but when would that get traded off? When would allthose extra horses start to decrease MPG? I've seen people say that turbo and SC can actually improve MPG, I guess I'm missing something because I don't see how.

 

Most everything you mentioned will give some sort of mpg increase. But you don't wanna use 0w-30 unless you live in a relatively cold place year around. The 0 indicates that the oil will be thinner for easier start up in cold temperatures. But if you have that in your car during the summer the oil will get way to hot and be really thin, too thin, and hurt your car. A common misconcepion is that the W stands for weight when it actually stands for winter.

 

Thanks, I'll add that to the long list of info that I've learned on this site. Guess I'll stick with my 5w-20 Mobil 1. and i assume that those performance up grades would yield mpg gain if you could keep you foot from turning to lead. in that case wouldn't a turbo also produce mpg gain?

 

Yeah, basically the turbo, when not in boost, atomizes the air and allows for a much better and efficient air and fuel burn. But if you are in boost constantly then there is going to be more air and more fuel being burned. So obviously if you are in boost then your gas mileage will decrease. Someone else will elaborate I'm sure but if not there are loads of threads on this subject.

 

OK i dont know about the Underdrive pullys but i do know that MDS ignition will help because it takes less gas to start your engine, Hi flow cat will help because it releaves pressure on the motor keeping it cooler and allowing more air to flow through the system. exhaust works in the same way it releaves pressure in the motor allowing it to run at a cooler temp. I will second the motor oil statment. I really dont see how the grounding system will work so i have no comment on that. I hope that helps

 

Any of these except tire pressure will not have any noticable positive impact on mileage

For most of them see mysignature

 

Oops - sorry for double posting []

 

drive like an old lady and watch your MPG skyrocket. lol