Newer (90's) versus Older (80's) Ranger fuel economy

[fastpakr]

Much has happened since this conversation- I removed the PCV, and replaced my ECU with a standalone programmable ECU, and the difference so far is big. The engine runs so much better, and I tuned it for optimal fuel flow and it runs better in all phases. I am getting 25 mpg on the highway, and 19-21 city now. The chip was a bad idea, thanks for heading me off- the ECU is the better solution. The next phase of this project is that I am back looking at rear diff improvements- the truck zips around nicely now, and since I live in flat lands, I am considering going to an 8.8 with a 3.08 gear ratio. This may boost economy as well. Bear in mind that I don't carry heavy loads, and I am not rock climbing. The rear diff needs attention anyway, so I am going to start looking for a replacement.

What standalone system are you using?

 

[scotts90ranger]

The 8.8 stock tall ratio is 3.27, 3.08 is a 7.5 stock tall ratio... back in the day I ran that ratio with 195 75 14 tires and if I remember right was around 28mpg with the fuel mix of the day (no ethanol)

 

[Josh B]

I took my tire sizes from a michelin site, I think there are also others.
Went from 265 to 235, I don't recall all of the exact numbers, but the bottom line came out at a 7% change.
On a turnpike with mile markers it showed at ten miles 10.7, so I think it's all pretty accurate
At 53.5 mph I am doing a flat 50 etc

My gas mileage actually improved from around 19 to 22-24, including the changed factors

 

[sdevine]

What standalone system are you using?

I went with Stinger Performance PiMPx, which is a Megasquirt computer rigged for the Ford Ranger, Mustang, etc., they also have very good support through their support forum.

 

[corerftech]

1990 Frankentruck
Bastardized by a resident of Mississippi before me.
De-bastardized as best possible after acquisition.
2.3, OE everything. Dual plug.
No AC (ala Bubba)
Unknown gear, haven’t serviced the carrier yet)
5sp
Very high mileage JYD replacement engine,
87 octane, religiously gets 22 in town.
I have run 75 mph hard for four hours to Pine Bluff and back again to get parts and I was getting 24 on interstate. Exceptional economy compared to EPA estimates from 1990 and age of engine. IMHO

That was on an old fuel pump. Haven’t checked or driven much since new pump installed a few weeks ago…..and FP made a notable performance diff so I may have been a pinch lean prior (and truck originally had lean issues to resolve at acquisition/bubba)

Stock tires (skinnies)


I’d like to sell the truck to provide final funding for my other truck project…. But I also have a microsquirt laying here dying to get in something. I don’t think the crank trigger wheel is compatible and that means pulling crank pulley and that is where things stop! Leave well enough alone!

 

[19Walt93]

Much has happened since this conversation- I removed the PCV, and replaced my ECU with a standalone programmable ECU, and the difference so far is big. The engine runs so much better, and I tuned it for optimal fuel flow and it runs better in all phases. I am getting 25 mpg on the highway, and 19-21 city now. The chip was a bad idea, thanks for heading me off- the ECU is the better solution. The next phase of this project is that I am back looking at rear diff improvements- the truck zips around nicely now, and since I live in flat lands, I am considering going to an 8.8 with a 3.08 gear ratio. This may boost economy as well. Bear in mind that I don't carry heavy loads, and I am not rock climbing. The rear diff needs attention anyway, so I am going to start looking for a replacement.

Don't do it. Assuming you have a 5 speed, the overdrive ratio is probably about .7:1 so a 3.55 acts like 2.48's in 5th and 3.08's would act like 2.16's. It would end up making 5th gear unusable and probably hurt mileage. Couriers originally had 4 speeds and we were happy to see a 5 speed appear, then the complaints started. They kept the same rear end ratio and 5th gear was useless in the NH/Vt hills. Also, an 8.8 is heavier than a 7.5 so it would have more unsprung weight for your little engine to drag around.
Instead, install a vacuum gauge and try to keep the reading as high as possible when you drive.

 

[19Walt93]

Only very limited parts of texas are flat. Specifically, the southern parts from around three rivers and down, and west Texas.

Compared to NH, Texas is flat. A friend who's a pilot told me(jokingly, no doubt) that after flying over the country, NH and Vt would be bigger than Texas if you ironed them out flat. We have so few straight, flat sections of road that we name them.

 

[scotts90ranger]

Don't do it. Assuming you have a 5 speed, the overdrive ratio is probably about .7:1 so a 3.55 acts like 2.48's in 5th and 3.08's would act like 2.16's. It would end up making 5th gear unusable and probably hurt mileage. Couriers originally had 4 speeds and we were happy to see a 5 speed appear, then the complaints started. They kept the same rear end ratio and 5th gear was useless in the NH/Vt hills. Also, an 8.8 is heavier than a 7.5 so it would have more unsprung weight for your little engine to drag around.
Instead, install a vacuum gauge and try to keep the reading as high as possible when you drive.

My '90 back in the day had an M5OD like it still has, 3.08:1 gears and 195 70 14 tires (~25" tall), it did fine on flat, got somewhere around 26ish mpg most of the time until I started screwing with it... I don't remember it being all that bad to drive, sure 5th was just for cruising on the flats but 4th did fine... Would I trade back to 3.08's from the 4.10 my '97 has in it now? heck no, but am curious what the '97 would do, maybe I'll get a wild hare one day and pull the 3.08 axle from under my Ranger trailer and put it in for funzies...

 

[sdevine]

Thanks for the input- so it looks like I might gain 1-2 mpg by going to 3.08, from what y'all are telling me. That does change things a bit. The new consideration is- does this yeild an overall improvement, and that seems to be a question mark for the time being. Now, I know the 4.10's are sought after for rock climbers and the like. I have read that the 8.8 is more durable and lasts longer that the 7.5 gears. Some people will junk the 7.5's without discussion. Well New Hampshire, you have a point, and yes, we are much flatter here- I mean flat. I can drive 150 miles and not change altitude more than 150-200 feet. Then the question becomes- will my 85hp engine be working harder that it has to with the 3.08? Perhaps we lose the benefit. What truck did the 3.08 come in? Was it the 2.3, or was it the V6 or both? Anyone else have a truck with the 3.08 that can give some feedback?

 

[scotts90ranger]

From what I've heard the 3.08's were mostly in 4 cylinder trucks as they usually had the smallest tires although some 4.0L came with 3.27 geared 8.8 axles at some point...

I pulled the 3.08's about the time E10 was phased in which seemed to drop the mileage by a couple at the time if I remember right, I didn't know much back then and just drove...