Cat Trucks to Get Cummins SCR, 15L in Doubt

by Tom Berg, Truck Editor | November 16, 2012

Cummins parts in a Caterpillar machine? It will happen soon as a result of partnerships among manufacturers, but the tie between Cat and Cummins in only indirect.

The machine is Cat’s CT-660 on/off-road vocational truck, based on Navistar International’s PayStar and built by Navistar at its plant in Garland, Texas. CT-660s use Navistar diesels that, starting next year, will be equipped with selective catalytic reduction (SCR) equipment from Cummins Emissions Solutions. Those engines will also go into the Cat trucks, with Cat’s approval.

George Taylor, director of Cat’s Global On-Highway Truck Group, said he and his colleagues are OK with the Cummins gear, whose technology they know about through Cat’s own work with SCR. Cat dealer technicians will be trained to work on the urea injection equipment, just as they now maintain and repair current CT-660 components from various suppliers, he said.

Navistar turned to Cummins for help last July when it abandoned its stand against SCR and needed to quickly get its diesels into compliance with government emissions limits. In addition to the Cummins emissions gear, Navistar has begun buying Cummins’ ISX15 diesel for use in many of its heavy duty trucks and tractors instead of its own MaxxForce 15, which it is dropping.

Cat was expecting to get the Navistar 15-liter engine, which happens to use a cylinder-block design from Cat’s old C-15, for the CT series trucks. So far Cat has been using Navistar’s 10.5- and 12.4-liter diesels, which it calls CT-11 and CT-13. Almost nine out of 10 customers choose the larger engine, he said.

Cat will almost certainly not use the big Cummins engine, Taylor said. So what will it do for a 15-liter engine? Possibly nothing.

“The industry is increasingly moving toward 13 liter” engines anyway, he noted. “There are now more 13s than 15s sold industry wide.” That’s true with certain truck builders, who all have proprietary 13-liter-class diesels that they’ve made standard in most Class 8 models.

To meet strict exhaust emissions limits, engineers at the builders have made great advances in combustion technology and electronic controls. These have also made 13-liter diesels far more powerful than in the olden days, when 400 or 430 horsepower was about it. Now the 13s make as much as 475, 485 and even 500 horses, with torque to match. Is any more power needed in a dump or mixer truck?

So maybe Cat doesn’t need a 15-liter engine after all. Taylor didn’t say that, but commented, “On the 15, we will announce something before end of this year.”

With the 11- and 13-liter engine models, sales of the CT-660 vocational trucks are going well, Taylor reported. Company policy prevented him from disclosing sales numbers, but said they represent the slow, steady growth that fits with Cat’s historic long-term strategy. And Taylor is fine with the announced closing of Navistar’s Garland plant, which builds the Cat Trucks.

“Caterpillar as a global company has always spent a lot of time balancing production worldwide,” he said. “And that the company (Navistar) is doing this to improve its health is a positive. The plan is to move production of the truck to Escobedo (in Mexico). It’s an ISO plant and produces some of the best quality. We will go through a ramp down and a ramp up, probably in the March-April 2013 time frame.”

Also next year, Cat will extend the CT range with a CT-680, which will have a forward-set steer axle needed in states with bridge-formula laws that encourage longer wheelbases. The current CT-660 has a setback steer axle for axle-weight states.