Driving tips to help a Cat C15 to be better on fuel.

hello all, I've been a member since 2015 but this is my first post.

A previous employee at our company retired at Christmas and the boss gave the freightliner truck to me to drive all the time.

It’s a 2005 with a BXS twin turbo. It used to be at the factory 475 hp, 1,850 tq. The retired trucker had Cat boost the power to 550 hp, 1,850 tq a year ago (light duty power or something he said).

Right now I’m trying different ways to get the better mileage out of this truck.

I’m looking for some advice and driving tips to help improve this truck as it’s the most thirsty in the fleet compared to our older 3406B Cats and a 1998 Cat (not sure what engine it is). I drove a 330 Cummins M11 for 4 years before getting this truck.

I just had the truck tuned by a tuning company instead of Cat as I don’t like how they setup the programming.

The tuning guy had the egr and some other things turned off which is great, finally! No more engine lights coming on and reduced power. Cat won’t do this.

Now the truck has 575 hp and over 2,000 tq.

Man what a difference! This thing sure pulls hard!

I keep my foot out of the throttle as much as possible and limiting boost to 20-25 psi unless I need more.

The boost gauge maxes out at 55 psi and the needle smacks it when the pedal is all the way down.

I understand this truck and the way it’s set up (truck specs in sig) is not for the best on fuel, but it’s the one we use for 5 axles and B-trains.

The engine spins 1,500 rpms at 62 mph or 100 kph.

I’ve noticed the mpg improves a little when I drop the rpms a little more to 1,300 or 1,400 and speed down to 56 mph or 90 kph.

But, the retired trucker said before he retired, the engine must never be running at low rpms or I will blow it up.... only have it running between 1,600-1,800 rpms.

The retired guy never cared about fuel economy as he’s not paying for it but I do as I know my boss does care how much he’s spending on fuel.

Thanks for any info.

 

I Glide 47:
I figured the Cat engines are pretty tough. I’m not sure where this guy got those ideas from that low rpms would blow it up.

He’s the one that chose this truck and my boss bought it for him I think 6 years ago.

All those years of wasted fuel while I did the same job as him with the m11 Cummins...

Snowwy:
Yup, it’s pretty nice of the boss to let me have the truck tuned.

I got his permission and went ahead.

He knows I respect his equipment and I do all the wrenching on them.

For other employees, that may not work for them.

The boss accepted the truck being tuned because he’s tired of sending the truck to Cat everytime let’s say a VVA engine code pops up and cuts power in half. That’s pathetic.

All that crap has been turned off.

 

X1heavy: our trucking business is a little slow in the winter so I haven’t had to use the trains yet with the new tune.

But I did haul some salt (vehicle cancer causing agents) in a tridem dump trailer.

The Cat pulled it like it was empty while grossing 116,000lbs. Never slowed on any little hills.

Soon we will be hauling logs on the b-train, should be fun!

 

Magoo: I look forward to the warmer temps! Lol! Be nice if it was here now.

Redforman: I have an app on my phone that allows me to keep track of each tank when I fill it up.

When I started driving it, the mpg was 3.3 mpg (Canadian) or 2.76 (us)

After driving it a little on the 550 tune and looking for the sweet spot, it got a little better.

After the tune and driving a little to work with it, it improved to 5.23 mpg imp, 4.36 us.

Blessedman: I’m hoping to get the kitty up to the 6 range if possible but likely may not happen but my boss is happy with whatever I can get out of it as long as it’s not 3.3 all the time.