Hi All,


New member here from Kali. Previously owned an '81 E-100 straight 6 with a 4 speed. I could get 20+ mpg with the right tail wind. That rig was running strong with over 300K on the odometer, when I traded it off for a '68 C10 short bed 454/T400 combo conversion.


I'm looking at another 6 cylinder auto (C4?) shorty, a '90. I was curious if I would be able to massage similar mpg out of this rig as it's sits? I've heard about a few electrical issues with the injected motors. The long term plan is to go through the motor, tranny, and rear end (adding posi), doing what will help to accomplish that mpg goal (any spares I should carry?). This going to be my retirement-travel-to-see-the-grand-kids-far-away rig. I'm not opposed to a diesel conversion at some point before rebuilding the gas components.


I'd normally be looking at a '72 VW Westy, but the spousal unit needs AC, or someone will die, and the Westys are getting big money these days.


Thanks, PAX

 

I think you will need an OD trans to see 20+mpg from an EFI van, I can get that from my '06.. the newer Triton motors are more efficient than the old pushrod V8s but it still takes the correct powertrain combo(engine/trans/axle gearing) to do it which unfortunately Ford still manages to mess up more than they get right.

 

Welcome

 

Welcome to FTE...nice forum we have here.

I had a '78 F100 pickup (ordered it new) with 300 and 4 speed OD. It would always be good for 20+ mpg on the freeway, even 22-24 if I held to the 55 mph national speed limit in those days. But the gearing was stupid--a 2.75 rear axle plus the .7ish OD gave a final drive ratio of 2.19 and the sucker would not go up the smallest hill in OD. So I have mixed memories about that truck. The OD would also eat the countershaft bearings because it was really not designed as an OD (it just used 3rd gear with the ratio reversed).

The F100 and old E100's were a lot lighter than newer trucks. My F100 was a short bed flareside and I believe it was ~3600 lbs. The van you are looking at will not have OD and I am not sure if it would have a lockup torque converter. And it will have way more weight.

My current E150 is an '02 with the 4.6 and a 3.55 axle and it is the best mpg van I have owned over the years. I had an Eaton posi installed in it when it was new. It will legitimately get 17-18.5 mpg on the road at 70 mph and I am guessing I could touch 20 mpg if I drove it 55 or 60 mph.

For you, I vote for a newer van with the 4.6. You will also have things like an AC system with R134 instead of R12, airbags if you do get into a wreck, etc. The 4.6 got and gets much better mileage than the 4.2 V6.

The old 300 inch six was a great motor, but it took crazy gearing to get big mpg out of it. I much prefer the 4.6 even though it has to spin a bit by design when you get on it.

Good luck,
George

 

And one more thing to keep in mind, (when comparing the mpg we got 30 years ago) is that back in the day, we all bought gasoline that wasnt cut with 10% ethanol.

Meaning, the gas nowadays has about 10% less available energy. So any older vehicle that used to get say 20 mpg, might be doing well to get about 18 mpg now. Its not likely the fault of the vehicle...just blame our government.

Not trying to start a political thread, just reminding you to keep your expectations in line with the reality of the crappy fuel we have today.

 

I think you could pull 20mpg from a 90 E150 with a 4.9 EFI, as long as it isn't worn out. stock 235/75/15s in an LT, C range at 50psi rolls a lot easier than a P235. you will have a C6 in a 1990 if no overdrive. otherwise an E4OD with a OD cut out button on the dash. if it has 1, D, and OD on the shift indicator its an AOD.


depending on your gear ratio, and if you have an OD trans will make a difference. and your driving habits make a big difference.


don't be afraid of the EFI inline 6, they produce a lot more power on a lot less fuel than the old LOG in and LOG out manifolds with the 1 barrel carb.


good luck in your Van quest.

 

I don't think 20 mpg is doable with the oldie.....the EPA ratings on the 1990 van are 13/14 with the 3 speed auto and 14/15 with the OD auto. (I think the ratings were 1 mpg higher before revision.) My '78 F100 had EPA ratings of 19/28(!?).

 

had both 300 6cyl 1 barrel 4spd manual with the "log manifolds and 1 barrel carb, and the 4.9 efi with a 5spd Mazda. 300 could barely break 13mpg even with a fresh tune and a rebuilt carb, 4.9 EFI 5spd could double that on the highway no problems and run circles are out the carbed truck.
I had to wait for 2500rpm plus to think about shifting the car motor, could shift at 1500 if I wanted to with the efi. carbed moter couldn't pull it self out of a wet paper bag, efi motor pulled like a little diesel!


4 barrel offy intake/carb and a header was the only way to wake up a carbed 300 6. otherwise they are a turd, but a turd that will run forever and get you crappy mileage and have no power, yeehaa

 

I can believe the EFI 300 would do far better than the 1 barrel carbed one, but you are saying 26 mpg on the freeway in a full size truck? I say no way. A Taurus with a 3 liter engine and EFI could barely get 26 on the freeway with about half the frontal area of a truck...

The OP is talking about an automatic transmission van so do take that into account. Ford is known to have really optimistic EPA ratings and the ratings on 1990 auto trans vans were 14-15 mpg freeway.

Peace out,
George

 

oops , my numbers are for an imperial gallon 4.54 litres and US gallon is only 3.78 litres


take all my numbers I posted and multiply by .83 gets within decimal points.


My 1989 F150 4.9 5spd broke 26mpg/21.6US on a regular basiswith 3.08s
my 1981 f150 4.9 4spd (OD) couldn't break 13mpg/10.8US under same conditions, no matter how I massaged the driving habits with 3.25s


mostly highway commute into the GTA 2/3 highway 1/3 city. same size 235/75/15 XL .


I try and calculate every tank of fuel I put through my vehicles. in May made a trip to Indiana and back with a 2002 Taurus 3.0 , avg of the fillups was 37.5 mpg/31.1US

 

That makes a pretty big difference. My wife's '98 Sable had a 3.0 Duratec and I think we cracked 26 or 27 mpg on exactly one trip. Normal trip mileage was 24 or so. We put 90k miles on that car so I remember the mileage pretty well. It did have climate control and ran the AC compressor probably much more than I would have with manual AC. And if you had the Vulcan engine I believe that did a bit better.

We can deduct 10% from all of our historic mpg numbers to reflect the new gasohol as the poster above noted.

I also put 90k on my '78 F100 with carbed 300 and 4 speed OD and it would usually get 22-23 on the freeway (but back in the days of the 55 mph limit). I did one hypermiling round trip to Cleveland from Detroit and touched 25 mpg, mirrors folded, tailgate down, Arco Graphite oil (yikes), drafting semis, etc. In that day and age it was amazing for a full size truck--but it was 3600 lbs. The EPA's on that truck were 19/28.

Aren't Canadian miles only .61 US miles?

(I live a block and a half from Lake St. Clair and less than 4 miles from Windsor as the crow flies, and speak fairly fluent Canadian, eh?.)

George

 

Your 81 had other issues if it couldn't get better mileage then that. It should of had no problem getting 18-20 mpg. You either had a carb, compression or a timing issue. My old 86 F150 with a 300/ NP435 4 spd got 10 mpg's while towing a loaded 20 foot car trailer. And it had a feedback carb that was causing it to run way to rich. And I also drive my vehicles like I stole them. I'm no hyper-miler.

Slap a restrictive intake and exhaust manifold and a undersized 1V carb on any engine and it will be down on power. And add to that the 81 was also hampered by emission crap. You don't need a 4V carb or headers to wake up the 300. The dual efi exhaust manifolds work quite well and a 2V carb also really wakes up the 300.

If the carbed 300 was a turd I wouldn't be swapping one into an extended E350 club wagon in place of a 351W. My van in no light weight. And it will be my tow vehicle. And I'm not the least bit concerned about it not having enough power to haul the loads I need it to.

 

its only a turd in stock form, a 500cfm 4barrel and pair of those EFI exhaust manifolds would work awesome . and will improve the fuel economy to within EFI range.


I've driven at least 4 maybe 5 of the 1barrel 3006cyl trucks and they were all pretty useless . we had a joke about them.
" couldn't pull the skin off rice pudding " custard works too. LOL


I was amazed with my 89 4.9 EFI, only problem I had was in the winter it wouldn't run warm enough. a 205 Tstat helped that out.

 

Ooops....cleaning the kb and somehow I hit submit?

It wouldnt let me delete it...dang...

So I had to fill it with this meaningless message...

 

That's funny. Because I have never had any issues hauling anything with any of the numerous ( more then 10 ) carbed 300 powered trucks I've owned. And some of those loads where a 52 Ford F6 grain truck that barely fit on a 20 foot trailer. A 10,000 lb. load of scrap metal on a trailer. And more vehicles then I can count. Ranging from 2 VW rabbits at once on up through a couple different F6/F600 grain trucks. And the only mods any of those trucks had was the one had a Hooker performance muffler behind a stock cat.


But I'm also a guy that hauled cars/trucks with a light duty F250 powered by an EFI 302/np435 for 5 years. I wouldn't want an 300 powered tow rig with an automatic. But if it's got a NP435 I'm good to go. But I also live in Minnesota so I don't have any mountain passes to drive over.


And to get back to the subject at hand, Welcome echo1! To answer you question in your first post about what spare parts to carry. I go a little over board myself. But on efi equipped vehicles I like to carry a spare TFI module, distributor cap & rotor, map sensor, temp sensor, TPS, starter solenoid, ignition switch, belts, hoses and if it's a single fuel tank vehicle a new fuel pump and filter. Basically anything, within reason, that would keep me from getting home if it failed. There is a reason I like carbed vehicles! Fewer/cheaper parts to carry!!