Cummins vs. Cat

Yeah, but look how much easier it is to work on...now.

 

Just overhauled my CAT at 1,298,633 miles. Replaced turbo at 640k, injectors at 800k, waterpump at 950k, bearings at1,050k didn't need them though. Truck doesn't hardly know what a shop is. Watch water temp and keep rpm under 1700 and they run for.... well 1,298,000 miles. Everyone gets better fuel mileage than me until we run together with similar loads, then for some reason it takes more gallons to fill their truck

 

Funny isn't it. I always laugh when I hear about all these Cat killing Cummins powered trucks. They're like Bigfoot because only a few have seen them. I had a T800 with an N14 460hp and a W900 with a 475 cat and the cat would eat the N14 for lunch. A friend had a 525 N14 and it couldn't walk away from the 475 either. Even at the dyno competitions there isn't a high HP Cummins in sight unless it's a dinosaur KT. Even at the truck drags in Canada most are Cats or Detroits. Look I wish the Cummins was better then I wouldn't be so reluctant to buy a new truck. Ask Mr.Haney if he's ever had his butt handed to him by an ISX! Lol

 

The company I run for currently has 4 C15 CAT powered trucks. 04 T600 with 500+ and 3.58 (dont remember exactly) , 08 W900 with 475 and 3.36, 04 379 with 475 and 3.58 and an 03 century with 500+ and 3.58. Those are not tuned o/o trucks, though they are properly maintened. I have driven 3 of them except for the W900 for at least 1 trip to BC or Cali in the past. The CATs are smooth no doubt, nice shifts too, but I'm sorry, that's it... Nothing out of ordinary. Pulls uhm... an OK with a minus. Engine brake - NON. Not even close to a pre 07 ISX with 475-500 and same diffs. Again I'm comparing power, based on a long runs between eastern to western Canada or US for 5-10k mile run, montains and straights. Drag racers with their tricked out bricks are not heavy interstate drivers. Like I said before, tuned maybe a different story. I do admit that CAT blocks and internals are mechanically superior to Cummins.

Here is an example of my truck (see sig) with 800k before rebuilt. Recent trip from Montreal QC to Knoxville TN on I-81 south. You know the up and down grades through NY, PA, VA and less in TN. I had grinded rocks in bags. Total weigh almost 80k lb. I maintain my speed always between 64-65mph@1400-1450rpm. and start 90% of my upgrades at that speed!!! I had to split the 8th. only, that's it! And make it to the top at around 1200-1300 rpm. My truck does not have any ECM tuning, except for the latest Cummins calibration 550@1800rpm and 500@2000 with 1850tq., properly adjusted and I had my droops maxed out by request, other mods are in the list. I can't even picture the power of pre 07 ISX with 600+/2050tq originally unlocked to 2500rpm and 3.58-3.73 rears. I haven't had experience with pre ISX Cummins or past 07. I know that pre 07 ISXs are heavenly understated in power ratings from the factory. Before I replaced my turbo and had my EGR blocked at PDI intake and disconected, I had the truck on the dyno at Cummins with original 550 calibration. It put down 515 hp to the wheels with partially functioning egr and turbo, add to that around 15% drive line loss.

 

I,ve always hated how touchy the throttle pedal is on a cummins. On the mechanical engines after setting the hand throttle at night you either woke up freezing at slow idle or to the engine screaming at 2400 rpm. I've never had good luck with them, but a lot of guys have good luck and like them. They do seem more tolerant to high rpm and high temps and stuff but a well maintained and properly driven CAT always outlast the Cummins. Got a hard time seeing myself in any new truck with all the junk on them. Would consider glider but can't get W900L, but hell, mine doesn't seem anywhere near worn out yet.

 

NRG...what type of brake are those trucks equiped with? We have Jakes and Pacs...you can REALLY tell a difference in the Jake compared to the PAC...although the newer Pacs seem to be alot better than the old. If they are not properly adjusted they'll be weak also.

 

My family owns 3 trucks, 2 of them have the 475 CAT motors and the other is brand new that has the ISX600.. I guess the only big issue is trying to change the fuel filter on the side of the motor... It takes 2 guys to change it!! Between the frame rail and the other things around it you can't get your hand under it to hold it up to tighten it.. One guy has to get under the truck and the other needs to stand outside..
Other than that if we could have got the new W900L with a 600 CAT that's probably what we would have went with.

 

Cummins calls it "Interbrake" up to 600 braking HP, it's driven by the second head cam. Very powerful. It can hold a fully loaded reefer at 7th low at constant speed at around 1600rpm. going down on I-80 west before Salt Lake UT and the like. It's somewhat weakened with the EGR block I did. I guess it utilizes some of that backpressure for it's full potential.

 

This is a little out of the blue, but I was wondering what are some of the big differences between UltraShift Plus transmissions compared to a Manual 18 speed?

 

I think they are the same box, the ultrashift is just shifted by an ecm thru solenoids. It's not an automatic transmission.