Project: 25mpg 4x4 4.0L 1997 Ford Ranger
 

Hey fellow Ecomodders.
So for the past three years I've had a goal to hit 25mpg's in my Ford Ranger. I'm getting close...ish.

So this first post is about the truck. It's a 1997 ohv 4x4 4.0L V6 with a 5spd manual and 4.10 gears. I bought it in 2003 with only 45K on the odometer. It has Ford's old Twin Traction Beam 4x4 system, which was the first independent 4x4 front suspension. It's nearly indestructible, but in my research I've found that it weighs 200lbs more than an A-arm 4x4 suspension! I've had it weighed several times during runs to the quarry and the dump. It weighs in at 4005lbs without the topper. The topper is fiberglass and weighs 180lbs.... I took it off years ago as it gets much better city mileage without the extra weight.

The EPA on the truck was 15city/19hwy mpgs, so my goal of 25mpg is fairly ambitious. I've calculated every tank on this truck since I bought it. My mileage prior to ecomodding averaged 18.5 mpg's. Worst mileage was 14.0 on a cross country road trip from Minnesota to Montana; averaging 80mph, the old OHV doesn't breath well above 2750rpm and mileage plummets. The topper was on, helping aerodynamics, but that was more than offset by the extra weight of my xwife, dog, and 300lbs of gear. Best mileage was 21.75 on a 220 mile road trip heading east across Wisconsin. It was a warm summer day, with a small tail wind, cruise control set at 65mpg, and the topper on. That was the only time I broke 21 in five years of driving prior to ecomodding, so I'm left to conclude that the tank didn't fill all the way thus throwing my calculations.

Finally, I live in Minnesota, and the Winter impacts my mileage. The block is cast iron and takes a great deal of fuel to heat up to operating temp. While I averaged 18.5 in the summer, the winter average was about 16.5. I drove the back roads 6.7 miles each way to work, averaging about 30mph.

Here she is.... the Danger Ranger!
http://imageshack.us/a/img600/263/truckpic1.jpg

since it's 5 speed you should be able to get 25mpg...instal a fuel cutoff switch so you can do some engine off coasting and learn to coast instead of keeping on the gas pedal untill you really need to stop...also, winter is not gonna help you break any records but in the summer you'll do it

If you can lower the truck without a big expense probably help a lot, , and if you haven't already switched to synthetics in all the drive train will make a difference, you've got a lot of spinning metal there, I would recommend you call summit racing and ask them about redline oil for the trans etc, cheapest place I've found , definite off the line improvement, the trouble with gears is it's all sliding friction so drag city , my first experience with the red line in the rear differential on the Ranger was an immediate off idle boost . also if you can boost your engine intake temp by rerouting the cold air intake big help there also , doing that today on mine. and last but should be first block the grille.

I'd suggest a gear swap. 4.10's are a little much IMO. And the whole front suspension and axle can come out in about 45 mins so if you found axles in the junkyard with 3.73's or 3.55's it'd be a couple hour long project. My little 4 banger 2wd ranger has a 3.45 axle and let me tell you, that whole "1600 rpm at 65mph" is pretty awesome. And it'll still haul my 600 lb atv.

I tried driving 65 MPH twice, but slowed to 55 when I saw just how much the mileage dropped. A light head or tail wind will change my mileage by 3 or 4 MPG, so the 21.75 is believable.

Slow to 55 MPH, learn and practice DWL, and you should be very close to 25 MPG. Add a grille block and a kill switch, and you will be there.

Lowering doesn't help much and is difficult on the twin i beams cuz it messes up camber.

Since stock pickups are about as aero as turds, slower speed is important for good fe.

Might want to spend some time with the tire rack tire specs guide, you can probably get a tire and wheel combo thats pretty light in 15 inch size, also go skinny as you dare if you're not carrying to much weight, i went to 215 70 15's on my other 98 ranger i just sold and they worked well. maybe even skinnier on front only if you have to , aggressive tread designs eat fuel also , as far as i know, one of the experts here can verify this I'm sure.

as far as lowering goes, i was thinking about maybe going large diameter rear tire and lower it only in the back 2 " thus making the front equally high as stock and gaining a more effective gear ratio by going to a bigger tire. also i was wondering if just dropping the rear only would help out as loaded a truck can drop that much and still seem fine. might get a very slight FE gain due to better windshield angle or roof slope but not much i suspect. just thinking out loud here,

The 2.5L ranger 4x4 is EPA rated for 25 hwy.

Wow BackroadBomber, your technical skills definitely out do mine! I'd prep for a month to do that job! Anyway, did Ford make taller gears in the Dana 35? I was under the assumption that the 4x4 with the Dana 35 only came in 4.10's.

Thanks everyone for the comments. Frank is correct about the camber; Ford TTB requires proper ride height or it cannot be aligned. And I can't do different size tires front/back as it is a 4x4 and needs the same ratio's. I think I'll prioritize the Fuel cutoff on my list of mods.