Hey,
I might buy my friend's 1989 F-350 in a couple weeks. It has the 7.3L diesel in it, its 4x4, 5-speed, regular cab, dually, and has a flatbed w/ 5th wheel towing. I don't know about the gear ratio or how many miles are on it (I'll call him up sometime this week). He doesn't do much driving without a load. He says he gets about 10-12 mpg when he tows a 15k lb. trailer. Does that sound right? He's a mechanic, so i know he takes very good care of it and it should last a good while.

What kinda mileage do you guys get with your 7.3L non-turbo diesels? What can I do to help increase the MPGs? I'm getting this truck to replace my 460 (see sig) which gets less than 10mpg.

Any help will be greatly appreciated.

 

My 93 IDI non turbo with 5 sp and 4:10 rear end gets around 13 on the road IF I keep it at 55 - over that it really sucks fuel. You'll notice that it won't be the speediest on get up and go but it will haul forever and about 10 MPG hauling on the flats of Michigan. Best thing to do is use a good grade of fuel prefer cetane of 42. with the advent of the ULSD (ultra low sulfur diesel) coming out very soon. talked to Ford teck and they are saying that every diesel (pre 93) should be using a fuel additive to lube fuel injection system. I've been using B5 biodiesel for 7 years and haven't had any problems - only praise. runs better and quieter.

 

my 90 4x4 sc zf5 3.55's gets 18 as a daily driver & 11-12 towing 8000#.

 

Would replacing the injectors and glow plugs help? How much are they and which brand is the best? How about I remove the "soup bowl" (got this idea from http://Cat=0&Board=73idi1&Number=288...ue#Post2880981)
He also said the clutch is worn and needs a new one...would that help?
Any other ideas?
Thanks.

 

If I replace the injectors and glow plugs, would that help? How much are they and is motorcraft the best brand? How about if I remove the "soup bowl" (the thing that restricts the removal of the air filter)?
Any other ideas?
Thanks.

 

Glow plugs will only help to start the engine, it has nothing to do with the normal firing of the cylinder. If the engine runs great I wouldn"t change injectors. Only possible increase might be with a better air intake/filter and a larger diameter exhaust. If he is towing a 15K trailer with a 5 sp I would check out the clutch for problems. I had to replace clutch and flywheel to the tune of $2K a few years ago. My flywheel was one of the ones that couldn't be turned.

 

My 88 F-250 C-6 Ext Cab 4x4 gets about 13-14 mpg on average... Never broke it down between road, town and towing though..... As with all IDI's after about 55-60mph the milage drops drastically.... My five speed truck just like it gets 14-15 mpg and again I tow in 4th gear so I could do better on the road in 5th..... Injectors will help power and mpg if your existing ones are in bad shape... If they are good you won't see much benifit... Cut out the soup bowl and fab a fresh air intake... Get a bigger straight through exhaust. I changed my fuel filter out to use a FS 1000 from Fleet Gaurd... Same filter used on big trucks... Not sure why but my truck runs much better with that filter set up than it did with the stock filter. Just my $0.02. Good luck driver..

 

A simple thing which has helped me boost milage by about 1 mpg on my 91' 7.3l N/A is to put in a K&N filter, remove the soup bowl and replace the plastic intake scope with a stiff 4" ID hose pointed to the open space on the left side of the radiator for a fresh air intake.

The factory paper filter and air intake system are very restrictive on air flow into the motor.

 

Bigredtruck, he said the clutch is worn and he's going to replace it before he puts it for sale. If I get it, I'll get a K&N kinda setup. It has straight piped stacks on it. Thanks for the input everyone...Kep it comming!

 

Farmboy, if your are going to buy the truck, insist he puts a Luk clutch setup instead of the stock setup. Luk is a far supperior over stock. For more info...search biomass clutches. lol

 

My NA 7.3 w/ 4.10s, 5speed, 4x4, 33x12.50 mud terrains gets 18mpg after I put on a 3" true dual exhaust w/ 6" stacks, cut out soup bowl and ran 5" intake with KN air filter. Before all the modification I got about 12-14. I have also been using a very strong mix of Power Service in my fuel because it is going to that low sulfur ****.

 

Thanks for the idea bdford, I'll see him tonight and I'll see if he could put a Luk in it. I hope I can get at least 14 MPG with it. If it doesn't, O well its better than 9 MPG with my 460. lol

 

I don't need a new clutch.Any one else? The more the better!

 

I get around 12 with my 89 crew cab dully with an all steel dump box. About eight when I really load it down.

 

my 88 5 speed f250 geared 3.55 gets 23 mpg overall it's turned up injection pump and electronic pump hooked up because the cam lobe was wore off that mpg is that good keeping it about 2 grand constantly i know its turned up a good bit it'll roll thick smoke at anything past 3/4 pedal