Now up to 57.3 mpg at 60 mph in my 97 Saturn SC1

[philmcneal]

Originally Posted by rh77

I have to insert that this may not be true for automatics -- I've found my best mileage cruising at 55, with city driving being the killer. Even with engine-off coasting and/or neutral at the stoplights, it just takes too much energy to get going again (that's with a ease into 20% throttle until desired speed). Any other automatic folks with the same problem? If I did highway driving all day I could get in the high 50's.

if you conserved your momentum for the red light, that number wouldn't be as low 1st gear starts the worse FE killers ever. If you can trick your car into thinking to start out in 2nd, things could get better.

Or go on that road slower yes, even slower so that you don't even have to conserve momentum when you reach the light. The light will turn green for you!

[SVOboy]

if you conserved your momentum for the red light, that number wouldn't be as low Eye-wink 1st gear starts the worse FE killers ever. If you can trick your car into thinking to start out in 2nd, things could get better.

Or go on that road slower yes, even slower so that you don't even have to conserve momentum when you reach the light. The light will turn green for you!

The problems with automatics, my main man, are that so much of the power the engine creates is lost on the way to the wheels, which makes accelerating really really ****ty. Also, you cannot control your shift points or kill the injectors at all on deceleration. It's a bad game, lucky I'm getting out of it.

[MetroMPG]

Originally Posted by rh77

I have to insert that this may not be true for automatics

you may be right. my mom's camry doesn't shift into high gear until 80 km/h (around 50 mph). no way to short-shift an automatic.

that said, i've never done any FE-measured driving in an automatic, using engine-off coasting. until i did, i wouldn't be convinced that you *can't* beat highway figures with it (and other in-town techniques).

[kickflipjr]

If i baby it my car shifts into high gear at 34mph.

[rh77]

The problem is, I can't time the lights on the Missouri side of town -- if a car is waiting at the light, it could change, or it could stay green. What kills me, is when 3rd is pefect to accelerate slowly, and it kicks-down to second. Dammit! I have 1st and 2nd lock, so I can start in 2nd if I felt like it, but after that, the automatic Gods render free-will useless. I end up stopping and going often, but I'm getting the engine-off coasting down. I just have to keep an "eagle eye" on the opposing lane and startup at yellow and get in gear or else I've got honking maniacs on the backdoor.

Story hour: If I didn't have to race to get a family member's birthday cake, I'd be at 40, but now I'm down to 36. There's some hope left: 1/2 tank. On the same day my in-laws were following me to a b-day get-together. I started into an intersection on a green light (slowly I may add) and some #$*@ in an SUV ran the red light and nearly totalled Teggy, and maybe me. If I didn't use the peripheral vision to check if my in-laws were behind me, I wouldn't have the crazy SUV biatch, and I'd be looking for a new car from the hospital. She gave ME the finger, saw my light was green, then took off. My father-in-law about had a heart attack because he saw the whole thing unfold behind me. There were mere inches between matter occupying the same space. I hit the brakes hard and used the ABS to maneuver around the skidding SUV. My blood pressure consequently went through the roof. Then we all went for miniature golf, and all was right with the world. 3 over par aint bad.

[mikefxu]

Pictures to the Hot Air Intake
http://www.saturnfans.com/photos/showgallery.php?mcats=all&si=hot+air+intake&what=a llfields&name=&when=0&whenterm=&condition=and

[kickflipjr]

What year sl2 do you have? After looking at your photo gallery it seems to be a 91 or 92 auto. That intake looks like it could melt. Plastic that close to the header could be dangerous..

[cheapybob]

Here are the pics of my hot air intake, and one of the IAT resistance table.

http://www.saturnfans.com/photos/showgallery.php/cat/500/ppuser/20223

[ZugyNA]

A guess on the heated fuel/heated air type of mod is that you'd probably want to keep the air temps below 110-120 F or so in order not to reduce power too much...but also heat the fuel to around 135F...maybe up to 150F to gain mileage. I've tested this to increase mpg and power by around 10% or so.

Reasoning is that heating the air too much reduces available oxygen...while heated the fuel results in improved vaporization...since the fuel is what needs to vaporize.

I also think that maybe closing the extra air openings (other than the rad opening) causes higher engine/fuel temps that increase mileage...rather than it being an aerodynamic effect.

With an EFI car that recirculates the gas constantly thru the gas tank...I insulated the bottom 2/3s of the tank with some thin closed cell insulation and got maybe a 10 F rise in fuel temps. Also blocked the extra openings in the front to increase engine bay temps. Plus I pull air from behind the rad...intake temps around 100-110F.

All this is still in the testing stage though. Just thought I throw out the ideas....

[JanGeo]

Somebody needs to check the shift points in an automatic with a vacuum gauge to see if it is being controlled by engine vacuum. I think it is pump pressure in the automatic and that requires tapping into the transmission with a pressure gauge to figure out when the shifting occurs. Either way you guys over 50mpg are doing great. Wish my Geo was road worthy to test some acetone and aero mods with.