About the new 4.5L GM diesel engine

[curmudge1]

Another article out about the new GM diesel engine, it is going to be light in weight:

http://reviews.cnet.com/8301-13746_7...logPromoArea.2

FWIW.
--
Dave

[gophergunner]

Can't until they finally come out.......I'm going to have to go for a test drive thats for sure.

[Freightliner3]

I think I will wait a couple years and see what happens.Where I come from heavy engine components mean durability and long life.I remember the light weight Cummings V/8 used in the Grove hydro cranes in the early 80s.They got rebuilt every year,it was a disaster for the owners and operators.Take a look at the new DD15 engine.I know it's for a big rig.But I would expect some of the owners will over load their rigs just like we do with 6.6 Duramax trucks.
I hope it works out for GM.But I won't be the first to buy one.

[trbankii]

Considering all of the issues that they've had with cracking on the 6.5 blocks, I admit that I am more than a little wary of all this talk of trimming down the bottom end.

I admire their goal of having an engine that is indistinguishable from a gasser in size and weight - just makes the concept of swapping it into other vehicles that much easier - but I just hope that they did their due diligence with the engineering this time and aren't letting the bean counters dictate too much of the design.

[George Schweikle]

The issue here is "product specification". With computer-aided design techniques, such as finite element analysis, the strength of components can be established very accurately. Designers can now determine the strength of different bearing web designs and something can be designed to be as strong as desired. This means as strong as listed in the product specifications, and here is where the variable comes in; stronger ultimately means heavier or more expensive materials and this means more cost. If GM wants to design a 100,000 mile Diesel engine that costs $X, they can. If they want 200,000 or 500,000 miles, they can do this too, but it will cost more. The potential problem is that product specifications are usually determined by the marketing department, not engineering. Engineers can only design to specifications, and I hope GM marketing realizes they need a good, robust, engine.

Considering all of the issues that they've had with cracking on the 6.5 blocks, I admit that I am more than a little wary of all this talk of trimming down the bottom end.

I admire their goal of having an engine that is indistinguishable from a gasser in size and weight - just makes the concept of swapping it into other vehicles that much easier - but I just hope that they did their due diligence with the engineering this time and aren't letting the bean counters dictate too much of the design.

[trbankii]

The potential problem is that product specifications are usually determined by the marketing department, not engineering.

That was exactly my point - how much getting you to buy a new vehicle after 100K miles was figured into the design decisions...

[Dimsdale]

Two issues: GM needs a light duty truck Diesel. The smaller vehicles, the smaller SUVs, and perhaps large cars, need a Diesel option. They have the Duramax for the big stuff, but one Diesel that is directed towards high fuel economy vs. pulling power is conspicuously absent from their stable. They used to have that, with the 6.2L Diesels, but took the path towards big engines/big output rather than smaller engines/high fuel mileage. They also need a really small Diesel four and/or six cylinder for small and medium sized cars. They have these engines on the road in Europe and Asia, so design time will be low. All they have to do is make them emissions compliant. Yeah, easy for me to say, I know! ;-)


Planned obsolescence: Given the current state of affairs with the economy etc., GM cannot afford to have a "make it wear out and they can buy a new one" attitude. It clearly didn't work with that Olds derived Diesel, and will be even less effective now, with current competition from Ford and Chrysler, as well as upcoming Diesels in the imports. Toyota is currently working on putting a Hino Diesel into their biggest pickups. GM has to consider that, as well as the current "import is better" mindset of the public, which the imports are happily exploiting to the detriment of GM et al. Clearly, the reality (or perception) is that you can already buy cars and trucks that will easily break the 200K barrier from imports, and buyers will obviously migrate to them if GM builds engines designed to fail (in my defense, I have always owned domestic trucks, and never had one achieve less that 300K miles). Perception is reality, and GM has to overcome the perception of unreliability if it plans to be more than a subsidiary of Toyota.

If they don't realize this now, then they are going to go down in flames. They have to earn their buyers, not expect them.

[rustyk]

The longevity of imports even in the '60s was a clue Detroit and Dearborn didn't heed. Overseas buyers could then afford only one or two cars in a lifetime, and wouldn't tolerate constant breakdowns, and the manufacturers had to accommodate that need.

With few exceptions, Japan supplied vehicles with those features. American manufacturers didn't until it was nearly too late.