Gas Mileage 5.0

[Elutheros]

I'm frustrated with MPG! I was getting near 16 with the A9L ECM (5.0/GT40P heads/Explorer Intake/3.73 gears/31" tires/M5ODR2 trans/EDIS ignition/no A/C) Only change was to install MegaSquirt MSPNP2 ECM. My tune looks good on all the plots and it runs great except for some stumbling at less than WOT at 2800-3200RPM. Now I'm getting 13MPG. I may have hit a wall in the HP vs. economy but I'd sure like to get a couple more MPG.

 

[85_Ranger4x4]

Basically the same truck here but with a 4bbl on a mutt Mustangish 5.0HO (E7 heads, HO cam, Weiand Stealth intake on a standard 5.0 with cast flat top pistons) and topper loaded heavy (two people and a bed full of gear) on my way to roundups I can get 18mpg @ 60mph pretty regularly.

It might take him a bit to get around here again but @PetroleumJunkie412 is really into the megasquirt stuff.

 

[Elutheros]

I should have mentioned that cruising speed here in Texas is 70-75. The little brick pushes a lot of air at that speed (2300RPM @ 75). I also have the HO cam.

 

[Bird76Mojo]

Could be a difference in the factory A9L being sequential fire and the MSPNP2 being batch fire..?

 

[scotts90ranger]

That probably doesn't help, but seeing all the area on the AFR curve that's under the 14.7 range means you're burning more than necessary. Whether you're running closed loop or not you don't "need" to run at 14.7 +/- a little, for many areas you could run a little leaner and just have it richen up for acceleration. Being a certified emissions setup a stock computer is going to try to stay at stoich at all times unless near WOT or probably above 3000rpm.

I haven't played with any of the megasquirt stuff or anything automotive yet, my life is in the industrial world (that doesn't even get into power enrichment or open loop) or marine world that goes way rich at times to keep the valves cool... that and I'm using a full on computer running 8 coils and 8 injectors in that world...

 

[Elutheros]

Basically the same truck here but with a 4bbl on a mutt Mustangish 5.0HO (E7 heads, HO cam, Weiand Stealth intake on a standard 5.0 with cast flat top pistons) and topper loaded heavy (two people and a bed full of gear) on my way to roundups I can get 18mpg @ 60mph pretty regularly.

It might take him a bit to get around here again but @PetroleumJunkie412 is really into the megasquirt stuff.

I'm sure I'll never attain 18mpg, but a constant 16 would be nice!

 

[85_Ranger4x4]

Yeah, running that fast you are not doing that terrible. If you could get 16 before I would think you could get it again.

 

[Elutheros]

I decided to do some research through the records I keep on my Ranger. I log every fill-up and maintenance I do on the truck in a notebook so I have lots of data and can see problems easier. The problem here is my memory! For the last 40,000 miles it looks like 13-14mpg is the average number. I hit 15 a couple times and 16 a couple. And, when I first started driving this thing to and from my hunting grounds I was cruising at 65 vs. 70-75 now.

Even after I converted to an aftermarket ECM, electric cooling fan, etc. it didn't change much. So I'm on a tuning binge right now. I created a new AFR table in Tunerstudio and reverted to MAF tuning. (I had gone back to my Speed Density tunes to see if they improved mileage--NO). I'm going to creep the timing up in the cruise areas and see what happens. I'll report back after a couple hundred miles of testing.

 

[PetroleumJunkie412]

Am I seeing this right? That your VE table is consistently 100+?

 

[PetroleumJunkie412]

Also you're running crazy rich at high engine load... do you have your spark set that far in advance?

More fuel doesn't always equal more power...

 

[Elutheros]

Am I seeing this right? That your VE table is consistently 100+?

That's because I'm running MAF tuning and since it's normally aspirated I never get beyond 100 MAP. My current tune VE1 and Ignition table are attached. I advanced the cruise ignition by 2 degrees and generated a new AFR table which I've beed tweaking as I review my datalogs. I am making progress! Back up to getting 140 miles on the first 1/4 tank instead of 120-130. The attached log was almost all cruise at 70mph with no hard acceleration--that's why it's almost all lean.