I notice Popular Mechanics seems very pro-diesel and did a report on the VW Polo:

Another manual transmission vehicle being compared to the automatic Prius.

Popular Mechanics also likes the Jetta diesel:

(Both photos come from Popular Mechanics web site.)

I notice these Popular Mechanics high mileage claims occur on the highway and not from the EPA test protocols. Any idea about why that may be the case?

One of the reasons I prefer the EPA test protocols is all vehicles follow the same driving profile in well defined, standard conditions. It is a vehicle test that can be reproduced by anyone.

Bob Wilson

 

That is correct 1stpik. Another factor to consider is the option of using biodiesel which, in most areas, also costs more than gas but may be more environmentally and politically frirendly.

 

Biodiesel is less expensive than regular diesel here in Vancouver, B.C. Owners also have the opportunity to brew their own Biodiesel for much lower fuel costs, but it's not very popular.

Diesel normally costs more than petrol in cold climates due to demand for home heating oil, etc. particularly in Winter season. Batteries are also less efficient in cold weather, if that makes any difference. Diesel prices will likely dip below 87 octane petrol prices again in the Summer.

Since you're comparing overall vehicle costs, we may need to factor in the extra performance of the Civic's larger displacement diesel engine (8.6s 0-100km/h compared to 10s for the Prius), diesels' high resale value, or their inheritently longer powertrain life.

What I'd be really interested in seeing is a orange-to-orange hybrid vs. hybrid comparison, i.e. gas hybrid vs. diesel hybrid. The diesel hybrid vehicles in Europe are yielding very impressive MPG figures. There's a reason FedEx or UPS are opting for diesel-electric hybrid for their multitude of small delivery trucks that cover countless miles. The joe-public diesel-hybrid vehicle however will likely be more expensive than the gas hybrid counterpart, so one still won't have a significant advantage over the other.

Cheers to high MPG vehicles regardless of fuel used!

 

One issue missed here is that this test was essentially 100% highway driving.

This is the worst case efficiency for the hybrid and best case for the diesel.

In city driving the hybrid would likely do a lot better than a diesel.

 

Not a lot, but a bit, maybe. Diesels are ****ed efficient in city driving due to their ability to get incredibly lean.

 

D a m n is a bleep word here? Well I'll be forked!

 

Add regenerative braking and they will be even more efficient. One interesting approach might be a modified "Jake brake" that exhausts into a high pressure container. Later, when the diesel needs to accelerate, the previously compressed air might be used instead of fuel for the initial acceleration. But as it stands, current diesels convert their kinetic energy when stopping into brake pad heat and wear.

Bob Wilson

 

Here's an article on a similar head-to-head test drive done in Europe. Try to look past some of the more inflammatory statements. Remember, Europe is HEAVILY biased towards diesel power.

http://driving.timesonline.co.uk/tol...cle3552994.ece


Peace,

Martin

 

Biodiesel from algae had a nice peace in Time last week. Seem to be catching on, hopefully this will bring the price down considerably.

 

Wow! Talk about the ultimate factory -- THE OCEAN AND PASSIVE SOLAR!