1996 Ford F150 4.9L (300ci) I6 5MT 4x4 - Page 3 - Fuel Economy, Hypermiling, EcoModding News and Forum

wriley4409 · 02-03-2010, 11:41 AM

One very big improvement that I have not seen discussed in this thread is switching to fully synthetic lubricants in the transmission, transfer case, and both differentials. There is so much friction going on between the sum of all of those moving parts that switching to a good synthetic lubricant would make a really big difference in your fuel economy.

Christ · 02-03-2010, 12:11 PM

Quote:

Originally Posted by wriley4409

One very big improvement that I have not seen discussed in this thread is switching to fully synthetic lubricants in the transmission, transfer case, and both differentials. There is so much friction going on between the sum of all of those moving parts that switching to a good synthetic lubricant would make a really big difference in your fuel economy.

OH, we didn't discuss that because everyone who frequents this forum already knows that I'm probably the 2nd biggest synthetic oil monger there is. LOL.

I checked the door card on the driver's side, since I just bought some tires from a guy and was already out there anyway.

Axle - 19
Springs - K4I
Calibration code (for paint? not sure) 6-51H-R06

Guess I should go look for a Axle# 18, eh? Does anyone know the actual tooth counts of the ring and pinion gears for a 3.08, in case it's been changed from another truck? People do that, ya know...

Also, does anyone have the spring codes and what they're for?

Christ · 02-03-2010, 12:32 PM

I found this -
But it's under the passenger side dash, instead of the driver's side. Still OBD-II?

I guess it really doesn't matter, my scanner will read it even if it's OBD-I, but it's nice to know, ya know?

I only ask because the Grand Prix I had also had the OBD-II connector, but wasn't OBD-II.

tpwalsh · 02-03-2010, 12:43 PM

is it a 1979 or a 1997? if it's 1997 it's required to be OBDII

Christ · 02-03-2010, 12:46 PM

It's a 1996... the title says so.

And no, it's not. There are 2002 F-series trucks that still have OBD-1 on them. It depends on the weight designation of the vehicle, and I don't remember the cutoff point for it.

EDIT - Turns out that, in theory, anyway, some 1996 150's were OBD-I, and others were OBD-II. It all depends on where it was made, and what parts they were using up at the time, being the end of a generation.

Mine is an 11/95, which means it could still be OBD-I.

Christ · 02-03-2010, 03:28 PM

Regarding the axle ratio -

It turns out that my Father actually has an 80-something F150 with an axle tag that says 18. Yep, 3.08 ratios.

Caveat - They broke the rear end about 13 years ago, and he doesn't know if they actually replaced it with a 3.08 or not. I can at least get the front diff, though, since I know that's still OE.

Guess I'll have to count teeth on that rearend and hope for the best?

I've looked around and found that I should be counting 40/13 to get a 3.08 ratio.

Turns out I have a Dana44 front axle, as well. Gonna see if I can find anything lower than 3.08 for the D44.

Darn. I'm not seeing anything lower than a 3.08 without going to a completely different front axle, and as much as I'd prefer a solid axle, I'm not doing that much fab work. 3.08 it is!

Looks like I won't be able to use big-truck tires, either. The 9.00-20's are 40" tires, and that's wayyyy too big!!!

I guess I'll stick with 15's, and just get some stock steel 7.5" rims and use the stock 235/75 tire.

Big Dave · 02-03-2010, 10:52 PM

Unless you raid the axle off an older Cadillac Fleetwood, even 3.08s are hard to find. The aftermarket no longer supplies the 3.08 set I have.

Bigger diameter tires will hurt you mileage. Stick with the OEM size tires. Sizing tires is one thing the OEMs do well.

I have talked to hundreds of truck guys and the story is always the same.

Bigger diameter = lower MPG.

Christ · 02-03-2010, 10:56 PM

Quote:

Originally Posted by Big Dave

Unless you raid the axle off an older Cadillac Fleetwood, even 3.08s are hard to find. The aftermarket no longer supplies the 3.08 set I have.

Bigger diameter tires will hurt you mileage. Stick with the OEM size tires. Sizing tires is one thing the OEMs do well.

I have talked to hundreds of truck guys and the story is always the same.

Bigger diameter = lower MPG.

The Caddy has an 8.8 rear end?

I'm almost certain I've got the Dana 44 gearset for the 3.08's in the front, it's just down to whether or not they replaced the 8.8" rear with a 3.08. If not, there's only one more option on a truck that we have around, and that's the mountain truck, and I'd have to switch axles to keep it movable.

The other Ford we have is 2wd, and has a axle code 17, which is either 3.25 or 3.31. I think those are too far off to use against a 3.08 in 4x4 mode.

tpwalsh · 02-04-2010, 08:44 AM

you REALLY don't want to put different ratios on the front and back, that's a recipe for a torn up drivetrain.

Christ · 02-04-2010, 11:38 AM

Quote:

Originally Posted by tpwalsh

you REALLY don't want to put different ratios on the front and back, that's a recipe for a torn up drivetrain.

Obviously not. If they're within 2-3%, it won't hurt anything, though, because it's within manufacturing deviation.

Unfortunately, 3.25 is a far shot from 3.08. Of course, if I wanted to do it that way, I could compensate for the difference in axles by using different sized tires between the two axles.