CUT are operated in light duty service compared to field tractors. Also they are used for much fewer hours per years than a primary field tractor. Nobody uses a CUT working at max power and max rpm from sunrise to sun set four months of the year. They mow the lawn, roto till the garden, use the loader to carry materials, use the backhoe to dig holes , run a pto generator 24/7 when loaded for a few hours before meal time.
I'm going to help you with your analogy since you didn't set it up right ... and then smash it to bits for you
So in many posts you've associated "light duty" with mowing, some tilling etc., while "HD" or heavy duty as "field tractors" pulling 9 rows or something like that. But somehow cars/trucks have been the bulk of whats been. So to take your language and make a proper framework for the analogy, lets use the transportation industry since that's whats been mostly discussed here.
So when you talk about "light duty", you're talking about cars/pickup trucks and HD would be semi-trucks (something extreme like 'field tractors' plowing). OK, in light of that framework I can somewhat relate to your light/HD comments.
Now, you said GDI would be cheaper in the "light duty" applications. Well, I've pretty much beat that one to death already ... no lighter application than a passenger car. I showed you the economy of my 2002 and 2006 TDI's, of which no non-hybird GDI can currently beat. But you don't want to hear about that, you want to hear about Tier IV ... and you want to go with EPA MPG numbers and not real world tests. Edmonds did a GDI vs TDI test. Apparently they used the EPA estimated MPG numbers so you should whole heartedly accept the results of their test without question.
The TDI won (but just barely). Their tests (ahem, estimate) had TDI at .74 cents a gallon and the gassers all coming in at .76 cents a gallon.
TDI Versus GDI - 2011 Volkswagen Jetta TDI Long-Term Road Test
I can tell you in real world numbers, the gap between the TDI and the GDI's in this test are much farther apart. I have a co-worker with a 2013 TDI and he gets much better than the EPA esitmate (again, EPA gives very conservative estimates for the TDI - everyone I talk too beats their estimate by a significant margin while they give inflated numbers for the GDI - which is why Ford, Kia, and others are going to court over it) and I have driven every car in the test except the Cruz. There is no comparison in the size, feel, handling, performance etc. of the TDI. The only one of the bunch that had any soul whatsoever was the Focus. If I couldn't have the TDI I would take the Focus. It is very zippy and fun to drive and handles very well. But it doesn't get the claimed MPG. I rented one just a few months ago and drove to Michigan and back (over 1,000 miles) in it and it was a pleasure to drive but I got closer to the 30MPG mark and it was all 100% highway driving.
It has been a while since I drove an Elantra but it had absolutely no soul at all. Didn't feel much different than driving an older Corolla.
To your point, the TDI was $2K more but it's trim level, size, handling, safety crash rating, and performace is worth that to me. The Focus was the second best out of the bunch but doesn't have the size, ecconomy or crash safety rating of the TDI.
If you compare actual real-world MPG, the TDI will make up the $2K premium if you want to count pennies. As long as I keep vehicles (and I usually don't buy them new so I don't pay the premium to start with), $2K extra is nothing if it is a vehicle I like and will keep for 10+ years.
So there you have it, Tier IV TDI vs 3 top GDI's using "fictitious" EPA numbers ... the TDI wins. It's on the Interent so it must be true. Bonjour!
