So been thinking for a while now about wether or not I should get rid of this IDI and get powerstroke. I'm wanting something a little more modern and a bit more "oomph". I'm getting really tired of the crappy fuel milage i'm getting from this truck, it usually goes about 350km before I have to refuel again and its starting to get expensive and its not really the type of vehicle that I want draining my wallet. I wanna be able to at least go on a long distance trip without it costing a gazillion dollars.

So should get rid of this truck and get get a newer truck, maybe a powerstroke that has a bit better fuel milage? I'm also looking at upgrades and costs associated with it. You cant really do much with an 89 as far as upgrades goes. Maybe a turbo and a better exhaust? I wanna get a chip, turbo'd, exhaust, lift kit and many more stuff...I'm just wondering if its worth it.

 

I like paying property tax on my 86, much cheaper than it would be on a late 90's Power Stroke.
I also like paying insurance on my 86, much cheaper than it would be on a Power Stroke.

When my 86 acts up, I get the tool box out and can fix it in just a little, where the Power Stroke would probably have to go to the shop to be hooked up to a computer.

And I also like buying a set of injectors for 200 dollars, not 2000 dollars.
Lets not forget that CPS that is 115 dollars and can leave you anywhere without a ride.

Can we say payment book?
I haven,t had to make a single payment on my 86 for 18 years.

If you gain 5 MPG, how many years to recoup the difference in fuel money and the truck upgrade money?

My answer for that is the Power Stroke probably won't last long enough to recoup the cost difference.

With the rebuild I did last year, I will not live long enough to need another truck.

 

That still doesn't fix the crappy fuel milage that I'm getting which is the main reason why I wanna get rid of it. 200 miles for a tank of fuel? come on....

 

I'm going to make a few assumptions here as far as insurance cost, so bear with me....

First off, Dave's mention of insurance cost is a very valid one. In BC where I live (public insurance), its less than $900 for basic + $1 000 000 liability coverage, My two older fords are actually the cheapest to insure in the house right now.

A newer truck is going to cost more to insure where I live, and I have a feeling its going to cost that much more where you are with private insurance in Alberta.

Secondly, I don't think that powerstrokes are better on fuel then IDIs. In general, they get similar MPGs, even though they have the advantage of better transmisions. There are also no emissions on the IDIs, so you can have your way with them in terms of upgrades.

What transmission do you have?

here's some of my history,

When my diesel came home, it had a C6 transmission, and 4.10 gears, top speed was 120 KPH, WITH oversize retreads on the back. Best MPG was, 12, avrage was 10, and worst was 9.

Less than a month later the gears were 3.08s, and the worst that I could manage was 13 MPG, average was 15, and when the planets aligned, just right 20 mpg was possible (at 100-125 KPH).

Now more recently, I also put a built up E4OD transmission in, and MPGs have not changed much, except the average speed is now higher when running empty, but most of the time, I am now towing a 20' flatbet trailer (now at 110-120 KPH average). On of my most recent trips had me cruising at 135 for much of the way, and to my suprise, when I calculated the results at home, I had got 18 MPG.

I should also mention that my injector pump is getting tired, and I need a fuel return line kit (air leaks), and its possible that I could do even better, but for now they're being put off.

Also, the freeway that I take here is not very flat, and its pretty much all long shallow hills for both directions (I also tend to drive more agressively in heavier traffic, so thats also killing some fuel economy for sure).

 

There's more to a truck than an engine than or gas milage that it's getting....a newer truck is just that....lets face it.....these trucks are so much of a personal thing, it's hard to separate feeling from common sense!

You know what the say....Boys and their toys...besides if we all had the same opinion, this would a boring forum!

 

In all honesty, my IDI is significantly better on fuel than my PSD ever dreamed of. If I stay light on the throttle, I average 17 in town, and anywhere from 21-25 on the highway, depending on speed(I usually go no faster than 110, that's 20 to 30 over in this neck of the woods,) without overdrive.
My PSD was a 00, 6 speed 4x4, and, at it's best, on long highway trips, it did 18.

You say 350 km per tank, how many litres does it take to fill at 350 km? My truck shows empty around the 200KM mark running around town, but only takes 34L to fill, and it's a 70L tank...

What transmission do you have? 4.10's are going to really hurt you if you don't have overdrive.
As for upgrades, you can do plenty to your 89, but, it isn't laid out cut and dried like it is for newer trucks.

 

You are exactly right about the fuel tanks, both tanks in my truck will try to show emply near the true halfway point, but if I wanted to, I could manage 400Km per tank on an average day (I think the stated capacity is 72 liters per tank)

I also agree about the diffy gears, especially without overdrive (if thats his situation).

 

i just added a turbo to my 1990 f250 and i have to say the power is amazing.
and before the turbo i could only get about 375 km out of 70 liters of fuel being really light on the pedal my best so far after the turbo being light on the pedal is 480 km on 70 liters

 

As I have said before, diesel MPG is more dependant on your driving style and the terrain where you live.

Also there are many ways to increase the power on both Power Strokes and IDI diesels.
And if you use the extra power on either of them, the MPG will decrease.

Buy the Power Stroke, then add the chip, bigger turbo, bigger exhaust, lift kit and bigger tires.
Every one of those mods have the potential of a big decrease in MPG.
Several of them like the lift kit and big tires will drop the MPG no matter how you drive it.
The more square feet of frontal area your truck has, the more power it takes to push it down the road.

The same is true for both the IDI and the Power Stroke as well as all other vehicles.

 

I have to agree. I would stay with the mechanical motor. Fuel milage can be helped. I have all the tooling and computer stuff to work the 7.3 PS and I won't have one. They can cost to much. I friend of mine had to have one so he picked up a 97 model for a good price and with-in the month he has paid out the nose. The injecter controller really hit him hard. He has put more in the truck then he gave for it and he knows the guy that he bought it from so there was no shady stuff. There are alot of people that has had excellent luck with them and they are, for the most part, dependable but when they do go it will cost.

 

Ok...got some facts now. So lets say I wanted 40 inch tires, turbo, and a bigger exhaust. Does anybody know what gear ratios in the diff will have how much of a decrease in RPM on the motor? So for example, on mine with the 4.10, I get about 2900 RPM doing 100km/hr or 62.5MPH. So could someone give me readings for 3.08's, 3.23's, 3.55's, and 3.73's and have the tire size included in that...I don't know the mathematical equations to figure it out. Any suggestions would be great.

 

I have had a 7.3L PS 1st generation (1996) and 2nd generation (2001) and a 6.0L (2004) all F-350 4x4's all of them left me stranded one time or another due to electrical faults or a bad sensor etc. My 93 4x2 has 188,000 miles and my 1988 4X4 has 183,000 miles. I have put most of the mileage on these rigs and how many times have they left me stranded ----ZERO----. The actual difference in miles per gallon the PS were equal to my NA IDI's but a tubo IDI would have similar power as a PS and better mileage. So, my next rebuild will be a turbo 6.9L.

 

Oh and if you guys are wondering, I have a C6. I've heard some bad things about the E40D's, so thats why I'm not too keen about getting one.

 

I have a 1987 F-350 dually 6.9, banks turbo, gear venders over/underdrive and exhaust brake. I had to rebuild the C-6 with upgrades sugested from this web sight. Then I had the injection pump reduilt to turbo specs and fine tuned and checked by Acme diesel in Knoxville and it's like driving a different truck. I was debating about buying a newer truck for power and fuel mpgs, but after getting everything tuned in I'm glad I didn't. Like Dave said, $200 for set of injectors or $2000, pluss, and, for me at least, a monthly payment, I don't think so. I would have done work on truck myself with all the help available on this web page, but no time and, according to wife, no patience, I spent less than 2 payments to fix problems and got a waranty. I agree with the rest, stay with your truck and save $$$$.

 

Well THERES your problem lol.

Now I fully understand your frustration. You basically have the same powertrain configuration that I did, and yes it did SUCK.

My E4OD conversion cost me in the range of 3 grand and that included many mistakes. I'm happy with the results, but the learning curve was steep, and I wouldn't recomend it to the faint of heart (otherwise known as sane people).

Dump the 4.10s.

Depending on what you plan on towing, I would recomend 3.54 gears, or even 3.08s.

3.54s will give you ~2400 rpm @ 100KPH, and 3.08s will get you ~2100 RPM @ 100 KPH (both estimates assume zero TC slip, so actual rpm will be slightly higher depending on load).

I should warn you though, if you go with 3.08s, you won't spend much time at 100, 110 or 125 is more likely .

Also, 3.08s are not avalable from factory, so a ring and pinion swap from and aftermarket gear cutter is your only choice for that gear ratio, mine were MotiveGear, and have performed flawlessly so far (aproximately 70 000 Ks).