Engines DO NOT MAKE peak power at idle. Period. And engine at idle is only making enough power to keep itself rotating.

You would need a HUGE engine or a HUGE idle load on the engine (ie. HUGE supercharger) to have an engine that is making 250 HP at "idle".

 

That's the bunus you get with an S-AFC, you can lean out the low throttle cruise.
My current around town mileage is about 17MPG.
My current LO map:
1000 0
2000 -15
2500 -24
3500 -26
4000 -26
5000 -24
6000 -15
7000 -10
And - yes I have a heavy foot.

 

haha, why would you even need to set your lo-throttle settings at 5000+rpm?? or is your lo-throttle/hi-throttle set up like dDub's?? 98/99. hopefully if i'm at 5000rpm+, i'm in hi-throttle.

 

on a good day= 17 mpg
on a fun day= 9-10 mpg

 

LMAO 250 HP at idle!?!?! God damn that would be one big engine

 

The map settings are there so I just filled them out.
About the only time I'm in low throttle at high revs is when double pedal downshifting.
Now if you want fireballs - that's where you fatten it up.

 

I have a freshly rebuilt 88 TII that is completely stock except for a mild street por. I'm in the break in period for the engine and very light footed. I worked my mileage out to a bout 10.6 mpg city driving. Does it sound like something is wrong.

 

I run a Haltech F10 with a distributor on my turbo vert and get about 18-20 mpg highway. I definitely need a good tune though bc my car guzzles gas at idle. Another "problem" (as far as gas mileage, at least) is that the stock turbo spools so fast that it can be hard to keep it out of boost. A wideband and a non-locked distributor would help my gas mileage a lot I think...

 

On the SAFC, you MUST set the entire range of adjustment, even for low throttle settings. It's hard to explain, but even if you don't USE 5-6K in low throttle, you must set their values properly...zero them out or ignore them and the entire curve changes with it.

Lets say your low throttle settings from 1-7K are -15% (not that anyones would be this linear, just using it for a point). Now, you assume that since you never use 5K-7K in lo throttle, you zero those values out. BAD MOVE. What you've done is changed the entire curve...any one change in the lo/hi throttle settings WILL modify the entire curve. Now changing by a couple % is no big deal but larger changes will have more of an effect on the entire fuel curve.

Remember, the SAFC does not have settings for every single rpm...only net points and ranges. The unit interpolates values for rpm points in between your settings.

The single most important factor in gas mileage IMHO is the O2 sensor since it is a primary source of closed loop mixture infor for the ECU. I replace mine every 2 years with Denso pieces.