Obama announced out of thin air that he was directing the EPA to mandate new MPG requirements for Class 8 trucks, mostly semi-tractors. What the EPA has already done to the Class 8 market is nothing short of breath-taking.
I first started big-time car-haul back in ’86, by ’88 I was running an 80,000 pound 65 footer with a large block 14 liter which got 6 MPG, a huge improvement over the average 4 MPG equipment from less than ten years earlier. In 1990, we had a small block 10 liter, rated at the same 300 horse power which got 8 MPG and was good for 10 MPG in certain applications.
Beginning with 2006 models, big trucks were mandated by the EPA to reduce particulate emissions, that puff of black smoke which appeared slightly when shifting gears, it is unburnt carbon which falls harmlessly to the ground. Diesel engines have never contributed to smog, they only emit CO2, not CO, as gasoline engines do. Pre-2006, larger horse power engines yielded better fuel mileage, if the gearing was set up correctly. (most fleets did not spec larger HP engines, since they cost significantly more)
Last year, I moved into a first generation EPA emissions unit, and I was towed five times, and lost 20 days of work due to the emissions system breaking down. Any Class 8 tow-truck driver will tell you that 90% of his tows are all new EPA-mandated 2006 and newer equipment, in many cases, these power units are less than a year old, sometimes this occurs within the first week of being put into service.
The 2009 Sterling that I am operating now is lucky to get 4 MPG, the older, pre-emissions 2005 model that I got out of was good for 5 MPG, and it was only towed once (the engine blew, it was long over-due for a rebuild).
Things got so bad that Caterpillar got out of the highway engine market altogether. They didn’t need the hassle, Class 8 engines was only a small part of their business. The EPA mandates added easily $20,000 to the price of an engine, and the manufacturer could lose a lot of that in warrantee claims.