There are several themes that run through almost any conversation about 2010 engines these days. Mostly they represent good news, we found as we talked to a variety of fleets in a follow-up to last October's "EPA 2010 Engine Scorecard."

Fuel economy is better, first of all. No severe mechanical or electronic issues are being encountered, so downtime is much reduced in some cases. Engine-makers are truly bending over backwards to service their customers. Drivers either don't notice the difference in engines or else they say the new ones "pull" better and are mighty quiet. Diesel exhaust fluid availability is an issue for some, but not for most, fleets.

The most common observation? It's still too early to know anything about 2010 engines in a truly firm, conclusive way. Some owners want another month, some another year, before casting their vote. Many just haven't bought any yet.

That said, there are those who are already convinced that their new diesels are just fine, and nobody seems to be frowning the way so many did at this same point in the 2002/04 and 2007 emissions regimes. So far there appears to be no real downside to any of the new diesels aside from the higher price - though that's no small deal. We encountered carriers that put off buying 2010s until they could no longer get trucks with EPA-07 motors, specifically to avoid the higher purchase cost.

C.R. England did exactly that, according to Todd England, executive vice president. The 3,600-truck Salt Lake City fleet was still able to buy the '07 engines into the third quarter last year. "We left it as long as - could," England says.

But then they went into the newer products pretty aggressively and now have one of the country's larger collections of 2010 engines. There are about 400 trucks in the fleet with selective catalytic reduction engines, 50 of which are day cabs and the remainder sleeper trucks. The sleeper trucks are Freightliner Cascadias with Detroit Diesel DD15 engines and the daycabs are Freightliner M2s with DD13s. They also have 50 International ProStars with MaxxForce 13 engines, which use an in-cylnder emissions solution instead of SCR.

Given the late start, it's no surprise that the odometers don't register big numbers yet. The maximum mileage on the Freightliners would be about 50,000, England explains; less on the Internationals.

England said he doesn't have enough data yet to make a true comparison between 2007 and 2010 engines or between the Detroit and International motors. Despite the lack of data, he did rather tentatively allow that "...fuel economy appears to be improved."

Too early?

The "too early to say" idea is a common response. All the carriers in last fall's article have racked up more miles, of course, and all have added more 2010-spec engines to their stables. But almost all remain cautious about concluding anything in terms of fuel efficiency. Some are so cautious that they declined to comment.

Con-way Truckload's Randy Cornell, recently installed as vice president of maintenance following Bruce Stockton's retirement, is in that camp. While the fleet has taken delivery of 216 MaxxForce-powered International tractors and 230 Kenworths with Paccar MX engines since September, he wants 12 months worth of data to really understand what's going on.

Many fleets didn't take delivery of any new trucks last year, and those who did were often in the fourth quarter. That means the most senior of those trucks might only have 25,000-35,000 miles on the clock.

Denis Martin, director of maintenance at Pitt Ohio in Pittsburgh, Pa., was decidedly unhappy with 2007-spec engines - he has 72 of them representing four engine makers in his 650-tractor fleet - so he was very "apprehensive" about trying 2010s. He took just one last fall, a Mack with an MP7 engine.

"We worked a deal with Mack so that we had one '010 to take a good look at and then move on from there. Now we have 21 of them, and those next 20 have been running for a couple of months." The first one has about 80,000 miles on it, the others about 22,000.

Martin also has added five Freightliner Cascadia tractors with Detroit Diesel DD13s, which also have relatively low miles on them.
Is he happy? Yep.

"When we moved into 2004 emissions, it was really a tough go. It got worse when we moved into '07s," he says. "But the 2010s, even though it's a little premature to say too much about these products, they've been outstanding compared to the '07s. I think, from a reliability standpoint, that we're back to pre-2004 emission days. These engines are pretty solid."

Another happy camper is a very small Canadian fleet mentioned in our story last fall. Stotesbury Transfer is a specialized bulk-liquid-foods carrier - milk and oils for the most part - based near Kitchener Kenworth, just west of Toronto, Ontario. That proximity made the 25-truck fleet a good candidate to be a development fleet for the Paccar MX engine.

When we first encountered the company, it had two MX test engines with several months of service in Kenworth T800 highway tractors pulling tanks with gross weights of up to 140,000 pounds on hauls as long as 500-600 miles. Those two engines were pulled and sent back for testing at the end of last year, replaced by production motors. Stotesbury has also added a pair of T800 daycabs for regional milk runs grossing 115,000 pounds. All four engines are rated at 485 horsepower and 1,650 pounds-feet of torque.

The new production engines are better, says Bruce Stotesbury, but even the test engines presented no huge problems. "We're basically just talking sensors that in some cases weren't performing quite up to snuff," he explains.

"The performance of the engines has been good, and we've gone nowhere but up in terms of fuel efficiency [compared to pre-2007 Caterpillar and Cummins engines]... There's nothing startling here, but we're real comfortable with the MX because it does well in terms of weight vs. performance. It's a nice weight/horsepower ratio for the tanker business."

Hirschbach Motor Lines in South Sioux City, Neb., has seen a similar smooth launch with no glaring issues so far. Jim Coffren, vice president, fleet management and maintenance, says the 550-truck refrigerated operation is in the process of a major update and last year he ordered some 100 new power units. Among them are 20 or so Freightliner Cascadias with Detroit DD15 motors and 82 International ProStar Plus tractors with 450-horsepower MaxxForce 13 multi-torque engines that began arriving in early December. The veterans in that group now have 35,000-40,000 miles.

"In general I would say... that we've been happy with both platforms," Coffren told us. "We haven't seen major problems that would mean taking units out of route or down en route. We've certainly seen some issues and some tweaking, but it has been very manageable.

"Those kinds of situations where you're chasing all the trucks and trying to deal with major campaigns and major parts interchanges, taking a large part of the fleet down for a day or two ... we haven't seen these kinds of things with the 2010 launch," Coffren says.

"So in terms of getting the trucks on the road and keeping them productive, they've both been very good."

The mpg battle

Fuel economy has indeed improved, or at least we think it has. It appears that a 3 to 5 percent improvement over 2007 diesels can sometimes be found - though not always - less the consumption of DEF in the case of engines using selective catalytic reduction. DEF-usage rates range from 2 to 3 percent, it appears.

In fact, a comment we heard a few times is that these new diesels are taking their owners back to the sort of fuel economy enjoyed with 2004 or even pre-2004 engines.

Pitt Ohio's Denis Martin sees things that way, saying they lost 8/10ths of a mile per gallon with the 72 2007 engines he has in