6NZ CAT ???

Tire size affects your rpms to go a given speed. 24.5 tall rubber rotates less to go same distance than 22.5 rubber. Although I have not checked out website there is a road ranger website where you can calculate engine rpms according to speed,tire size, transmission, and rear end ratio. This truck your thinking about might not be too bad in rear end department if it has 22.5's.

 

Okay... I get it.

Thanks

 

How many miles on the motor and if it was inframed does it have papers?

 

930000 Kilometers.

I don't know what 'inframed' means; I don't know if it has papers? This is all the ad says...

6NZ CAT MOTOR, Pro heat, Block heater, pan heater, Espar bunk heater, Wet kit, pickup ramps, car carrier front axle- 13,600 lbs, low air leaf, 63 inch bunk, Fridge, front tires Michelin XZA3 95%, Rear tires yokohama 527 80%, 3:55 gears, 18 double over trans,new compressor and govenor, all new silicon hoses, new clutch hub, new belts, 2nd Owner.

The truck is in Calgary. I found it in kijiji if you want the details?

I'm gonna ask my boss about it tonight; he is a straight arrow so he will let me know if it's right for the job or not and what it is really worth. But this is a big ticket item for me so I get as many opinions as I can. This is the information age after all, so there is no excuses for making a bad buy.

 

Puffrooster,

My personal experience with the 6NZ: though I more or less got out of trucking for a while, I've been driving for an owner/op for going on 4 years now, and the truck I run is a '01 Freightliner Classic XL, 273" wheelbase, 84" condo sleeper (yup - the big truck!), low-pro 24.5 rubber, and while I forgot to check the ratios, it's got a Fuller 18-speed, and a 6NZ C-15.

Now, I should mention that my boss is the 4th owner of this truck (the original owners were United Van Lines), and it now has 1.3 million miles on the odometer (well, 1.347 and change, now).

It's never been rebuilt: the second owner had the cam replaced (early ones weren't treated properly, and wore fast), it's had the injector rockers replaced with the current type (early ones were thinner, and they broke - I broke one in February, the shop found a second broken one, along with an intake valve spring that had been broken for so long, they couldn't tell when it broke!), and had one injector replaced at that time.

The original turbo was replaced 2 years ago. It's had a starter replacement, an alternator replacement, a couple of A/C compressors - oh, and an oil drain plug at the front of the sump, that a grease monkey at the local Petro forgot to torque down properly (the engine shut down when the oil level was too low, protecting the engine, just like it should), and we've had to pressure wash the radiator, intercooler, and A/C condenser a few times, to get rid of all the dead bugs, so that it runs as cool as it should without having to constantly run the engine fan.

Other than that, nothing's EVER been done to the engine, except for routine servicing.

IT JUST RUNS! AND RUNS! AND RUNS!

It's got 550 HP, can pull a 50,000lb load up & over Donner Pass at 55mph, without any strain at all. It cruises at 70mph at 1500 RPM, and while they say you shouldn't rev a Cat engine, it can rev upto 1900 RPM (again, not advised - but sometimes the high/low doesn't catch enough air when you shift it, and...), and it's equally happy at 75-80 MPH. It just hums along, and makes a wonderful sound. I usually shift gears @ 1700 RPM when accelerating.

All this, while moving a 22,000lb tractor around (what the Freightliner weighs...it's a BIG truck!).

Fuel consumption varies from 5.5, to 6.5 MPG, but again, it's got 1.3 million on it, so it's a bit tired, even though it still runs strong, and is more dependable & reliable than my boss's other newer rigs. It always starts, it always runs, and it always gets me from point A, to point B, and has never had to be towed in all the time I've been driving it.

In the 15 years that I've been driving trucks - and I've driven new ones, and I've driven pieces of crap, but there was something special in the air when the 6NZ was built. The only other engine I've experienced that were this reliable, was the Cummins "Red Top" N14 , but it usually needs a rebuild between 800,000 and 1 million. (the good part, is that its cheaper to rebuild than a Cat)

I often run from Reno, Nevada, to Calgary & Edmonton (over length permit for my tractor), and I may be heading that way tomorrow, so I can take a gander at it with you, if you like, and maybe if time permits, I can take you for a spin in mine.

Charles

 

Oh - almost forgot: 930,000 Km is 558,000 Miles: plenty of life left on the engine of the truck you're looking at.

 

Well that's mighty kind of you, Poor Mothertrucker (LOL), but I'm in Edmonton, not in Calgary; I have yet to look at the truck myself (although I'm pretty sure it's still there because the ad is still active).

As for taking a spin in your whip, I appreciate that as well but I'm using my bosses Peterbilt with the 6NZ inside and know full well how this engine performs. I especially like that whistling noise it makes; everything else it does can go without saying I'm sure!(?)

The newest Peterbilt I drove was quite recent, a 2014 with some kind of Cummins inside. (They) gave it to me brand new. It was okay I guess. It did what it had to do but if you shifted wrong, or the RPM was off, it gave out that, sputter, farting sound; that's all the plumbing in the pollution control parts getting in the way of trucking.

Even though it was a company truck and I didn't need to worry about fuel, I still kept track of it and worked it as if it were my own... and the mileage verses fuel consumption turned me off from buying new, not to mention the waste of time adding DEF!

After that, I went to an even worse place and left before the 3 month probation so I wouldn't have to give notice. I will just say that I was already on my third tractor, and the managers were fascist, nazis micro management, morons.

The place I'm at now is my final posting and forever home. I feel like I'm trucking again! I was given a 2001 (or 2002) Pete with a 6NZ inside and I just forgot what it was like to drive something that is just pure engine, so much so in fact that I'm willing again to possess my own ride.

Unfortunately, even though my finances are very good and I never was in trouble with any of the money barons, this is my third employer this year and I have only been here five weeks. My bank sees this as unstable at best. They like it if someone stays put for at least two years. In my case, five or six more months more will be sufficient for 150k, unless I put something up against the loan, (which I won't; If something goes array, they can have the truck back, but that is all. Of course if I buy new, then they will consider it!)

So I have no cash to bargain with at the moment; I would just be wasting everyone's time just going to look at the truck! The sellers, yours, mine...

I just have to sit tight for six months and tell myself that it just wasn't meant to be... and maybe play the lottery from time to time

 

What is the best rpm range on a 6nz with an 18speed hitting max 60mph for both power and fuel efficiency

 

Fuel economy a 6nz likes 1350-1400.

Pulling 1400-1700