bountyhunter
Well-Known Member
The title of this thread is really incorrect: if any adjustment to the engine results in doubling of fuel mileage (or even 20% increase) it means there was something very seriously wrong with it before. That is assuming apples-to-apples comparison in driving test. You can "double" mileage comparing steady speed driving at 35 mph to stop and go with hard acceleration.
Auto makers are under SEVERE cost penalties to meet CAFE fuel mileage standards and they are not leaving much on the table in terms of mileage. You can get some power increases with tuned intake/exhaust systems as well as "remapping" the spark advance and FI patterns but it's not a whole lot to be gained. I put the Weapon-R cold air packaqe on my Cavalier. The dyno tests published for it show maybe 6 HP increase.
Most people who start screwing around with sensors or emissions systems end up doing a lot more harm than good.
Auto makers are under SEVERE cost penalties to meet CAFE fuel mileage standards and they are not leaving much on the table in terms of mileage. You can get some power increases with tuned intake/exhaust systems as well as "remapping" the spark advance and FI patterns but it's not a whole lot to be gained. I put the Weapon-R cold air packaqe on my Cavalier. The dyno tests published for it show maybe 6 HP increase.
Most people who start screwing around with sensors or emissions systems end up doing a lot more harm than good.