Mileage vs Modifications

[GIT-R-DONE]

One thing I have noticed in here is that nobody addresses the fact of mileage vs the modifications. So my 1990 has 200,000 on it, is there going to be a problem if I mod the pump, turbo, exhaust etc? Should there be any concern about the engine holding up after the mileage on it or is there a time before the mods that maybe the motor should be overhauled? Ideas and suggestions welcome ... ... ... thanks

 

[formula]

Mileage in general isn't affected much by the usual modifications we do to our trucks. Seldom is there a decrease in mileage and often there is a good gain in mileage. The most significant factor in your mileage will be your right foot. Have a look at my mods in my signature. After all of that, my average mileage (16mpg) has remained the same, and I have a heavy foot Best mileage to date was on the trip to Muncie, 22. 5mpg.



As far as the engine and pump being able to handle increased power, that all depends on how far you want to go. A set of gauges, mild pump adjustments, a smaller turbine housing, better air filter and an exhaust system would be a great place to start and should not impact relaibility or longevity.



Cheers,

Sean

 

[GIT-R-DONE]

Formula, thanks for the reply. I am new to all of this web site stuff, but have owned many CTD over the years. I just never really modified any of them. I may have misstated my question. I was not concerned about the mileage per say MPG. I was more worried about the wear and tear of those miles and what those miles have done to the engine. Then all of a sudden I change all this stuff and then find out the motor is " worn out" or I find something else in the engine is not capable of handling the new additions. I know these motors are capable of many miles , I just didn't know if it would hurt the motor to change all this stuff after so many miles running stock. Thanks

 

[dpuckett]

cuda6pack,

I wouldnt be too concerned about the "high" mileage factor unless you have over 750K. Seriously. I had 255K on mine when I had to replace the head gasket (which was blown for almost 10K), and still had the cross hatches in the cylinders. You caould eat soup out of the valve covers. Since acquiring mine with 242K, I have put on a PDR HX35-12, guages, done some modest pump tweaking (AFC spring and pin settings). It had been "turned up" by Cummins Rocky Mountain many years ago, and I just got a hair more out of it. At sea level, empty, I can hit 34psi up a hill. No engine problems so far. I'd be more worried about the fuel system then the internals themselves. Go for it as if it had 50K. Power is about fuel and air. THese engines can take a lot. The pistons, bearings, rods, cam and crank, etc, are the same or similar to the ones used in 2nd gen trucks, and they make 700+ hp.



Daniel

 

[Withers]

My mileage has gone from about 720 kilometers per tank to about 810-830 kilometers since I had the P. O. D. injectors, and new exhaust installed , hard to complain about that.

 

[Bob Beauchaine]

I've got to agree with formula your right foot is probably the best tool you've got to control your mileage. Look at my sig and see what mods I've done. I still get 17 to 18 city and 20+ on the highway. My best to date was 22. 16 in it's latest configuration.



Bob

 

[tugboatphil]

The last two issues have had articles of million milers that didn't even do much in the way of preventative maintenance. When I shut down ol' Blue, my 90, it was because the rear end went out. Engine was still as tight as a break in. She didn't leak a drop of oil.

 

[JLEONARD]

I believe the longevity issue is more a matter of duty cycle than how much power the engine has the ability to make.

If you keep your foot into the firewall and use ALL of your available power as often as you can and you will shorten the engine's life without a doubt.



Same goes for mileage as has already been stated. The heavier your foot is, the lower mileage you'll get. In a diesel, fuel consumption is based on actual horsepower used, not by how much horsepower is available.

Actually, the general rule is that the more hp the engine is capable of the better economy you will get at reduced power levels. (At least this is true in the marine applications and it has to apply here as well. )

Jay Leonard



So with very little mods I get about 24 mpg on a daily basis... . so, new injectors and a modified exhaust might pay for themselves in increased mileage???

Hmmm..... I wonder if my "financial manager" will buy that argument.....

 

[GIT-R-DONE]

Thanks For all the imput guys... ... ..... Now I have to start the projects as the $$ is available. Although I am new to this site,

I have to say these forums are AWESOME