BIG van seeking 20mpg loaded

[mwilliamshs]

1989 E-150 4.9L C6 with 3.08:1 gears and 28.8" car tires. Has a ~4" tall fiberglass cap on the roof (pop-up camper top). Has had NO efficiency mods of any kind, just maintenance to get it road-worthy. I drove a Ranger 2.3 for a few years with a ScanGauge II and was getting 20% over EPA ratings consistently. DWL yielded the most improvement over my other hypermiling strategies. Truck was an automatic so P&G was out (for me anyway, I know some still do it) and ran heavier than necessary tires (for durability off-road and on crappy dirt roads).

Planning a big tune-up and a couple engine mods right now and doing aero research.

[elhigh]

Consider a trailer tail of sorts for your back end, belly pan and skirts.

The tall rear end helps a lot, keeps the revs down.

I used to drive a 15-pass van for work, approx the same age and never beat 15mpg, but I was exclusively doing city traffic. New brake pads every year and every year had to explain to the boss why I needed them: "Because I cover 25,000 city miles every year, Stan." If you're going to be mostly highway I think you can do it.

[cosmick]

I have an '03 E150-cargo, 4.6L V8 / 4R70W / 3.55:1 / LT235/75R15C, it does 22 MPG HWY, whatever the load in the back.
Having the straight-6 engine is no help because those have really poor fuel distribution, so they have to run rich enough so no cylinder ever runs lean.
Also, swap to an AOD, just for the OD. Grab one from a salvage yard for $75. Best possible return on investment. Then your 3.08:1 gears will be too tall, you'll want at least 3.27:1 gears. So there's another $60. By the time you add in fluids, gaskets and seals, you're looking at $250 to correct your gearing situation.
Converting to port injection would really help, but from a practical aspect, swapping vans looks best.

[mwilliamshs]

Originally Posted by cosmick

...Having the straight-6 engine is no help because those have really poor fuel distribution, so they have to run rich enough so no cylinder ever runs lean...Converting to port injection would really help, but from a practical aspect, swapping vans looks best.

LOL I have port injection already. 1 injector per cylinder, aimed directly at the back of each intake valve, fuel distribution not an issue. The 4.9L came that way from 1987-96.

The only efficiency gain from an AOD swap would be the lock-up torque converter. It's a weaker transmission and not well suited to vans. It's .67:1 overdrive is a poor mix with heavy vehicles. Driving at my engine's torque peak of 2000 rpm puts me at 56mph now, the AOD would raise speed to 83mph and the 3.27:1 you suggest would only drop it to 78 mph. It would require jumping to 4.10 axle gears to get 2000rpm to be usable (62mph) but those gears would be drastically less efficient at all other speeds. Anything above 60 or so mph is noticeably more work for this big box.

Your cost estimations are also horrendously low. A used trans aint $75 ($109.99 + 29.99 core) and it aint worth the labor to R&R a used unit twice. Gears might be $60 for you ($79.98 + 5.98 core for me) but an axle rebuild kit and the gear swap labor would be $250 easy. I can rebuild my C6 for about $300 and it's pretty darn easy. The much more complicated AOD is about $700 and way more work. IF my trans ever dies I'll rebuild it and replace original thrust washers with roller bearings to gain efficiency but barring that I plan no transmission swapping or mods other than temperature instrumentation and a deeper pan (from a 4wd F350) at the next filter change.

[cosmick]

BULL!
The way Ford locked up those converters wasn't good, which improved to the GM way by the time the AOD evolved into the 4R70W, but the AOD is strong enough that its core components can be retained in builds for 1000-HP Mustangs.
Using OD in a big van, hauling a heavy load, is something I do A LOT of.
The old myth of cruising at TQ peak is not borne out by modern testing of modern OD vehicles.
I didn't say 3.27:1 would be perfect, just using the next ratio down ( up numerically ) as an example.
My cost "estimates" aren't estimates at all, I go to Pick-N-Pull several times every year, doing these swaps myself for my own vehicles and for my friends. If you won't do the labor or can't choose good parts from a good yard, that's on you, not me.
The C6 is inefficient junk, a built C4 can hold just as much power with dramatically quicker elapsed times, despite virtually-identical ratios, proving the inefficiency of the C6.
You want to put an E4OD low-ratio set in your C6 to allow a 2.73:1 axle? Fine, try that.
You want to swap a B&M TorkMaster 2000 torque converter to drop another 150 RPM at cruise? Fine, do that.
But you can't approach my results by telling me I'm wrong when I'm not.

[mwilliamshs]

Not trying to argue with you. These are the facts. You've been wrong about the port injection/fuel distribution, and inaccurate about parts pricing. I got the prices I gave from picknpull.com and I'm in Little Rock, AR if you'd like to double check them.

Never mentioned how the locking torque converter works just that it would be better than the setup I have now, which doesn't lock at all. Also never mentioned swapping converters or planetary sets. Actually stated I plan zero trans mods except 3 very specific ones: a pan swap, a temp gauge, and maybe some bearings if I ever do a rebuild.

I said the AOD is weak. That's why it was put in half-ton vans, but not 3/4 or 1 tons. What you have is a much newer, much improved, electronically controlled version that shares just a few AOD-type parts. Apples and watermelons. As much if not more so as C6 vs 4R100.

Go shout BULL at livestock, not me.

[easythereturbo]

Getting away from the arguing a minute- If anybody out there seriously wants to push efficiency limits in a full size van.. check in with RP cars in Florida. They have left over composite unibody full size ram van chassis/bodies made in the early 90's for u.s. electricar. Will need tons of work to complete from bare bodies, but this is probably the only shot at getting chassis specifically built for efficiency in a traditionally shaped full size van. We're talking half the weight of a steel van plus improved aero. I don't think they have all been scrapped yet.. but if not they will be soon.

I thought about shipping one even though I am 3000 miles away and really have no use for it. Maybe somebody closer can save one from being destroyed and build something cool. Pm me for a phone number.

[cosmick]

You can't prove me in error about port fuel injection correcting the fuel distribution of any inline 6, but all inline 6s will have problems with air distribution unless using a fabricated intake manifold, of a design not workable without port injection, and such a project would cost more than just swapping to a pfi v6, a big old Ford van could use a newer Ford 4.2L V6 very easily.

[mwilliamshs]

Originally Posted by cosmick

You can't prove me in error about port fuel injection correcting the fuel distribution of any inline 6...

Are you saying that having an injector pointing into the port of each cylinder won't provide balanced fuel distribution to any engine, or just to inline 6 cylinder engines? If it's just inline 6's that you claim aren't properly served by this injection strategy, can you explain why? If you claim no engine is properly served by this injection strategy, can you explain why?

Originally Posted by cosmick

...all inline 6s will have problems with air distribution unless using a fabricated intake manifold...

Wouldn't any engine have a problem with "air distribution" without an intake manifold? Aren't all manifolds fabricated? My guess is that you mean custom fabricated as opposed to manufactured by a factory somewhere but that's obviously not true.

Originally Posted by cosmick

...unless using a fabricated intake manifold of a design not workable without port injection...

So you claim this manifold design must have port injection ("not workable without port injection") to provide adequate air distribution to be workable but port injection won't "correct" the fuel distribution so what's the advantage of this mysterious manifold design?

Originally Posted by cosmick

...and such a project would cost more than just swapping to a pfi v6, a big old Ford van could use a newer Ford 4.2L V6 very easily.

A) no interest in swapping a much less durable engine and B) the Ford 4.2L v6 was available OE in fullsize vans starting in 1997 so yeah, it stands to reason a van could use the engine as fitted by Ford.

You seem to have some idea that a v6 is inherently more efficient than an I6. Is that correct?

[oil pan 4]

Lose the car tires.