Our Engine Smarts item and November HDT column on complaints about 2002-2010 diesels ("What's Happening with Engines?") hit a proverbial nerve, because we got a healthy amount of reader response.

Evidently the fleet managers at that Technology & Maintenance Council session last September, who said that too many engines are causing serious troubles and too many dealers aren't prepared to deal with them, are not alone.

Now we can report that preliminary feedback to a survey being done by TMC further backs those comments. Basically…

* 2002/04-spec engines with exhaust-gas recirculation are more troublesome than their non-EGR predecessors;

* 2007-spec engines with EGR and diesel particulate filters are more troublesome than the ones that came before; and

* 2010-spec engines with EGR, DPFs and selective catalytic reduction are more reliable and turn in better fuel economy than the 2007s.

We've seen that breakdown before, but TMC activists are getting more numbers on it.

By "spec" I mean the equipment effectively mandated by the Environmental Protection Agency's performance requirements in the three stages listed above. These were the most strict exhaust-emissions limits ever published, and TMC people pretty much agree that they came in too short a time for the engine builders to really wring bugs out of the equipment.

Not to get political, but the run-up to the 2012 presidential election has begun, so I will: These regulations all came under a Republican administration in Washington. And the 1990 Clean Air Act under which the regs were written was signed by a Republican president.

Hey, aren't the Republicans supposed to be friends of business? Yes, but they also want to be friends of the environment, and it's true that when these engines run, they are so clean that you can't see or smell their exhaust. That's me you just saw, flip-flopping like any good candidate.

Anyway, the survey quoted above is now being put to all TMC members, but you don't have to be a member to participate in it. TMC's technical chief, Robert Braswell, has posted it on the group's website. If you've got experiences with these engines that you want known, click here to access the survey form.

Results will be shared at TMC's 2011 Annual Meeting in Tampa, Fla., Feb 20-23, 2012.

Fill out the survey (it's in pdf form) and submit it. If you're a TMC member and can get to the Tampa meeting to hear the results, go. You can go even if you're not a member, but I'd recommend joining because what you learn will save you money, not just on engines but everything else that makes a commercial truck run.