Our latest intelligence shows the Big Three's 1/2-ton diesel pickups are on the way. The problem is that none of the manufacturers seem to be in a rush to get them on dealer lots. As a reader of Diesel Power, you know that the GM and Ford 1/2-ton diesel engines were created in-house while Dodge went with Cummins to power its light-duty trucks. At this point, it looks like GM will be the first on the scene with a 1/2-ton diesel. (GM's last 1/2-ton diesel was a 6.5L in 1998.) Dodge is positioned next in line, although the condition of its overall business structure remains to be seen. Ford will introduce last, as a diesel F-150 would mean less profit from diesel Super Dutys and gasoline F-150's.
All the diesel engines have a few things in common-for example, similar displacements (GM 4.5L, Dodge 5.0L, and Ford 4.4L) and V-8 cylinder arrangements. Another thing they all share is a liquid urea emissions system known as selective catalytic reduction (SCR). Both Ford and GM use compacted graphite iron to strengthen their engine blocks and reduce weight. The Cummins and Duramax engines both mount their single variable geometry turbo in the engine valley as to increase emissions performance and simplify design. Ford, on the other hand, installed twin turbochargers. All diesel-equipped trucks will come loaded with the high-end premium packages, four doors, and six-speed automatic transmissions. Customers shopping for a stripped-down work truck will need to look elsewhere.
TOP SECRET
GMC Sierra and Chevrolet Silverado 1500
Engine: 4.5L LMK Duramax 72-degree V-8
*At least 310 hp and 520 lb-ft
*Aluminum heads and compacted graphite iron engine block
*Exhaust gas recirculation (EGR)
*Compression ratio: 16:1
*Variable geometry turbo located in the engine valley
*Catalytic converter and diesel particulate filter (DPF)
*Common-rail fueling with piezo injectors
*Selective catalytic reduction (SCR) through the use of liquid urea
*Chain-driven dual overhead camshafts
*Six-speed automatic 6L90E transmission
*9 /2-inch ring gear diameter in the semi floating rear axle
MPG: According to Diesel Power's October 2008 interview with GM's Executive Director of Diesel Engineering, Charlie Freese, the 4.5L Duramax is projected to have at least 25% better fuel efficiency than a similar gas truck under light load conditions. However, under work situations, this diesel engine is said to be 40-70% more fuel efficient compared to a similar gasoline-powered truck.