My little econobox

[cRiPpLe_rOoStEr]

Originally Posted by Deathscort

A worse CD? What's that, forgive my ignorance on that one. I wanted to do a BP swapped festival but its impossible to find the two for a reasonable price. Thanks again, and my car has no rust surprisingly, but its a NC car, transferred to MS. Bought it when I was stationed at ft. Bragg. Took a little getting used to the 1.9 after being in a 03 F150 supercab with a 5.4 lol.

CD: Coefficient of Dragging - the resistence imposed by the airflows to the vehicle's movement.

[mechman600]

Originally Posted by Deathscort

since its EFI, the increased voltage load retards the ignition timing.

I'm afraid it's not that simple.
It might slightly retard the timing to compensate for decreased vacuum caused by increased throttle angle. It has to in order to maintain correct timing.

The retarded timing isn't the issue. The issue is slightly increased load imposed by the alternator and subsequent slightly increased fuel consumption. And charging system voltage in itself has absolutely nothing to do with ignition timing.

[Stubby79]

He`s probably just reading the results on his MPGuino or whatever instrument of what happens when he turns on the lights. He sees the timing retard when the electrical load is high and it drops when it is low.

That being said, I would suggest seeing if you can find an affordable underdrive pulley. That`ll decrease the load on the engine all around.

[brucepick]

Ignition retard yes or no, more electrical load = more mechanical load on the engine. So reducing lighting load will help FE.

I'm not sure whether the LED swap by itself will be visible as helpful above the "noise" of random changes the car experiences daily. But it's a good move.

I realized a good 4-5 mpg improvement when I disconnected my alternator output cable. The car's entire electrical system now runs off deep cycle batteries, with no load on the alternator.

The improvement is even more noticeable when driving in rain. Wipers + fan + lights + (for defrost) a/c compressor clutch if available = much electrical usage. In a moderate rain I can now get essentially the same FE as on a clear day.

[Deathscort]

Wow, I love the responses! I've always been a more, more, more kind of modification guy, power wise. I'm enjoying learning a bit more about raising fuel economy. Next on my list is to learn about how to make a supercharged vehicle get good fuel economy....

A few pics...

[Deathscort]

Originally Posted by brucepick

Ignition retard yes or no, more electrical load = more mechanical load on the engine. So reducing lighting load will help FE.

I'm not sure whether the LED swap by itself will be visible as helpful above the "noise" of random changes the car experiences daily. But it's a good move.

I realized a good 4-5 mpg improvement when I disconnected my alternator output cable. The car's entire electrical system now runs off deep cycle batteries, with no load on the alternator.

The improvement is even more noticeable when driving in rain. Wipers + fan + lights + (for defrost) a/c compressor clutch if available = much electrical usage. In a moderate rain I can now get essentially the same FE as on a clear day.

The deep cycle batteries weight does better than the drain from the alternator? That's pretty good imo.

[Stubby79]

Originally Posted by Deathscort

Next on my list is to learn about how to make a supercharged vehicle get good fuel economy....

Depends on what engine we're talking about. The GM 3800 supercharged engines can get 30mpg real world in a light vehicle if you keep your foot out of it. The supercharger might cause a lot of drag, but it also increases the intake charge efficiency or some such.

Now if you're talking a big V8 engine, you're probably SOL.

[Deathscort]

It's on a RWD Thunderbird supercoupe.