New Cat dozers will no longer have letters in their model names. Here’s why.

Caterpillar D5

If you happen to notice that some of the model number/letter designations on Caterpillar dozers are getting shorter, it’s not your eyes that need checking.

The company started reformulating its machine nomenclature back in 2017 with the end goal of getting rid of the letter suffixes that follow the numbers. Here’s an example from the original article written by Marcia Gruver Doyle:

Under Cat’s former nomenclature system, for example, the former 745C would have become the 745D. Instead, the new artic reads “745” on the machine’s side with no letter designation, and the model is known through internal and external communications as the 745 (Build 04), with the “04” representing the fourth generation of the machine.

However, at the time the changes to model names started, Cat said dozers would be the exception to the new rule. Now their thinking has changed, and in order to make dozer identification easier and simpler to understand, the model name changes started three years ago will now apply to dozers as well (plus, with the T-Series Caterpillar was running out of letters). Big Savings on Dock & Truck Equipment . Save More at

“It follows an automotive strategy,” says Sam Meeker, product application specialist. “We’ve had a Ford F-150 for decades, but there has never been a Ford F-150 dash-1 or dash-2.”

Cat’s Sam Meeker talks through changes on the new D5 dozer.

We saw the first completed change-over at Caterpillar’s Cary, North Carolina headquarters in October when the D6N was updated and renamed the D5. And while a decision has not yet been made about which dozers will carry the new badges at ConExpo 2020 in March (likely the D4 and D5 though nothing is set in stone), eventually all the dozers will be renamed.

And within the next year or so you’ll even see a brand new number designation, the D1, previously known as the D3K2 and D3K. (See chart.)

The new numbers are based on the horsepower class of each dozer model. And not to worry, Cat’s not downsizing anything. The old D6T is being rebadged the D5 but it actually weighs more and offers more horsepower than the D6T. (See our article on the new D5 by clicking here.)

“This is an important change for us,” says Meeker. “We want to make sure people understand it and are not confused. The feedback we’ve gotten has been positive.” But as we’ve reported before, the simplified numbering system isn’t going to be limited to dozers. Eventually the whole of Caterpillar’s equipment lineup will undergo a nomenclature simplification, a move that started with the 745 articulated truck in 2017.

>>Chart: Guide to the New Cat Dozer Nomenclature

Gradual roll-out

The dozer names are not going to be updated all at once. Rather, Caterpillar will rename each size class once that size dozer has undergone a redesign or upgrade. The D6T, for example, was renamed the D5 this fall in concert with a host of new features including a mast-free GPS system, blade load monitor, traction control, new powertrain capabilities and a bump up in horsepower.

This is not to say that Cat dozer names won’t have suffixes. A few will remain. Because of their unique powertrains the hybrid diesel-electric drive dozers, D7E and D6 XE (introduced in 2018) will retain the “E” and “XE” suffixes. And the LGP (low ground pressure) tag will be kept on all models that have the wider tracks.

The other suffix you might eventually see on the dozers is the GC designation, which is already used on some excavators (320 GC, 330 GC, 336 GC ) and one wheel loader (the 950 GC). The GC moniker was used to denote a basic, no-frills machine with a lower cost and less technology than the more fully featured machines. Meeker says you might/could see this on dozers a year or two down the road.

Feature sets

In the past, the suffixes on Cat dozer names typically designated different feature sets. There will still be annual product updates and new feature sets for dozers and other machines, but contractors will need to know the year-model or the serial number to know which machines have which updates.

“The model year does a pretty good job of telling you what’s in there,” says Meeker. “But our customers are accustomed to serial number prefixes. The serial number prefix is like your middle name. Knowing the serial number prefix and the feature set attached to it is like a badge of honor for our customers.”

Caterpillar dozers typically undergo a redesign about every two to five years, says Meeker. “Depending on how big of an update that is, we may just do a serial number break. That allows us to be clear with customers and dealers as to when those features come into the line. For major changes, on a larger new product introduction, where we are changing significant portions of the tractor we will do a full serial number prefix,” he says.

The D1 and D2

In addition to renaming the dozer line, Cat’s reorganization of the nomenclature will also result in a completely new name, the D1 and the rebirth of the D2. The new D1 (the old D3K and D3K2) will be the first Caterpillar dozer to carry that number, says Meeker.

And while there has been a D2 in the past (produced from 1938 until 1957) the new D2 will incorporate the old D4K2 and D4K size class.

Three groups

Overall the new naming system will also make clear the three basic groups of dozers that Caterpillar offers. The first group, the D1, D2, D3, and D4, will replace the K family of dozers and retain their low-drive sprocket design. These are considered the light-to-medium duty dozers. From D5 and up you’ll see the Caterpillar’s elevated sprocket/high-drive design. The D5 to D8 dozers comprise a second group of dual purpose machines geared for both heavy dozing and finish grading. And the third group, D9, D10 and D11 will continue to be what they’ve always been—heavy push dozers.