C 15 Cat upgrades

[Rat]

Well the comapny I drive for is moving me into another truck. I was running an 01 Volvo with a VED 12 and could get just over 5 mpg on average. We haul some heavy stuff so it is hard to get decent economy no matter how you drive.

Well they sold it and they are moving me into an 04 Pete with a c15 475 hp.

I was out in an 06 379 with the same motor etc and I culd hardly get 4.5 mpg average hauling the same loads.

They have the truck gov out in speed but I rarely hit the gov unless going down hill.


Is there any tricks to getting more power and economy out of the C15 without having to bring it into Cat and spending huge money on it?

We get a fuel bonus so it is important to try and conserve if I can.

I had even tried driving it a 55 mph and that did not help one bit.

We pull 3 and 4 axle Trinity Eagle Bridge trailers with domes on them and we normally have 58,000-60,000 loaded into the trailer putting us at 92,000 to 100,000 depending on if we have a pusher on the tractor or not.

[marylandkw]

http://ohe.cat.com/cda/layout?m=164581&x=7

Boy that is heavy. Gonna make it hard to get really great numbers. I only run 70,000 pounds but have found I get really good MPG when shifting low and staying low. I make all my shifts under 1500rpms. Don't try to drag race off the line and if you have a 13 or 18 make sure you at the very least split everything on the top side.

Other than that as a company driver it is gonna be hard but as an O/O you could look into lower rolling resistance tires, better rear ratio and of course anything but a 379 It's gonna be hard (not impossible) to get good MPG with a brick.

[Orangetxguy]

Actually, at 100,000 pounds, 4.5 to 5 miles per gallon isn't bad, loaded. When empty you should be able to adjust that upwards. When I was hauling gas up in Seattle, the KW T800 I drove was in the 5.5 to 5.8 range..only because 50% of the miles were empty miles. The gross though was 105,500...unless I "overloaded" to much gas..say 12,300 gallons...instead of the 11,500 that was standard order.

Like Maryland said...use progressive shift. Keep the rpm's in a decent range. Use the cruise control as much as possible. I have an International 9400 series with the C-15 and am averaging 5.8 mpg over all, at 78,000.

[Rat]

As far as the rolling brick, LOL. We have T 800s witht he same motor and they don't get any better milage then the 379s.

The Pete has a 13 speed and I do split the top range but below 1500 rpm means that I won't be getting anywere. I shift right at 1500 rpm for the most part.


There used to be little tricks O/O used to do to fool these computers to make more power all the time. I used to hear about them when I was out around the country in my own rig. It has just been awhile.

I am not afraid to spend a couple bucks myself as I will gain it back in fuel bonuses plus I might beable to get the company to pay for it if it actually helps.

[Orangetxguy]

As far as the rolling brick, LOL. We have T 800s witht he same motor and they don't get any better milage then the 379s.

The Pete has a 13 speed and I do split the top range but below 1500 rpm means that I won't be getting anywere. I shift right at 1500 rpm for the most part.


There used to be little tricks O/O used to do to fool these computers to make more power all the time. I used to hear about them when I was out around the country in my own rig. It has just been awhile.

I am not afraid to spend a couple bucks myself as I will gain it back in fuel bonuses plus I might beable to get the company to pay for it if it actually helps.

Most of the "tricks" you hear about..were used on the old mechanical engines.

If you feel your pocketbook can handle the ding...fool with the ECM on that engine. Just remember..anything you have done to it...it will record.

[Rat]

I don't care what the computer records or tells the base shop when it goes in. The boss could careless what I do as long as I can save him fuel costs and not get any speeding tickets etc.

As long as I keep the truck clean and maintained and make him money then I am free to do as I please.

[Papa Rick]

Not understanding why your not getting better fuel mileage. I have a C-15 Cat, 475hp, can be upgraded to 550hp but will cost close to 1,000.

I haul logs for a living, avg 90,000 lbs in a KW W900L Day Cab, 390 rears, on 24.5 Tall Rubber. Avg is 5.2. I try to shift 1500 or under. I have raced from red light to red light, and my avg fell to 4.6, whew didn't take but one tank of this to realize that I may have beat the other guy, but lost big time in the wallet.

My friend has a 379 Pete with C-15 Cat and does not get but 4.8 mpg and gears are 353 or close to that???? Don't understand this as he should get better, but then again he does dog his engine alot.

[Rat]

Wel these C15s must be real bad. I was running an 01 VNL 670 condo with a 465 VED 12 and a 10 speed and I could easily get 5.1 to 5.5 in a days average. This was puling the exact same trailer with the same loads.

Only dif was that the unladen weight was about 500 lbs lighter with the Volvo.


If it were not for the condo sleeper being a pain in a side wind, and that it road like crud, I would have asked to keep it or get another.

It kept throwing me around in a side wind and would actually make me sick to my stomack.

[solo379]

Well, how it was explained here, take it easy. It's not just a speed, it's how you get to it. Be very gentle with the pedal, try to keep your RPM around 1300, pay attention to the turbo boost gauge, and pyrometr.

[Rat]

Well there has to be something a person can do to get more out of this thing then spending a grand at Peterbilt or Cat to get it to perform and get some kind of economy.

[Papa Rick]

I look forward to hearing what you find out, as mine is the same engine as yours, and every bit gained in fuel is a good thing.

[Rat]

Well Bully Dog is making a box for the non ACERT C15 but their website does not have it available yet. Supposed to up the power around 75 hp.

They already have them for the Cummins motors and the Detriots I believe.

[tracer]

I have a C15 Cat and originally it had only 435 hp. I paid about $1,000 to Cat to rerate it to 475 hp, and it felt like a different truck. Then I paid about 800 bucks Cnd for a "Dyno" and it cost so much because they not only measured the hp output but also tuned up the fuel settings. The mechanic later showed my a computer printout which stated that even though officially my engine had only 475 hp, I was now getting 500 hp at 1,500 rpm! The truck drives now again like a different truck Since you're pulling heavy loads, I suggest you do this Dyno and ask them to optimize your fuel settings. Your fuel mileage should improve since the engine will not have to work as hard as before.

[Rat]

That is soundling liek the cheapest option so far. The bullydog power up pack runs about 2500 or 2800 dollars.

I am going to check with my fav deisel guru and see what he says I quess.

I was just hoping for something I could do for a couple hundred or on my own to make it better without having to bring it into Cat or Peterbilt.

I have been a mechanic by trade since 1987 but I don't have the hook ups or the programing to get into the ECM on the big stuff.

I knwo it sure would be nice to find a pirated version of the software and some cables so I could hook my lap top up to it.

[Papa Rick]

Hey Rat, did you find out anything on your C-15 to get the fuel mileage up, and if so what was it?