On Tue, 8 Jan 2013 18:52:22 -0500, "Howard Lester"
Back in the day I thought it was tax differences only.
But diesel has more BTU value than gasoline, "should" cost a little
more per gallon, "should" give somewhat better mileage.
If it's that much more expensive now, I presume that's mostly tax
differences now cutting the other way?
they don't price on btu's unfortunately. otherwise we'd see prices go
down for winter blends and ethanol inclusion. better mileage on diesel
comes not just from btu's [which are now reduced as part of the low
sulfur rort], but also the inherently better thermodynamics of diesels.
it used to be priced according to what they wanted to sell. back when
gasoline trucks were more common and before modern refinery catalysis,
diesel was an over-supplied fraction of oil, so it was lower priced to
encourage use. now, catalysis means refiners are no longer hostage to
the distillation fraction proportions, and they can make virtually
whatever they want - all gas or all diesel. there's no technical reason
for pricing differences any more.
and you can look up tax differences, but iirc, they're minimal.
Yes, meant to mention, they don't water the diesel with ethanol!
But the inherent better thermodynamics used to come at a premium in
engine price and weight per displacement, but maybe technology has
yup, the "price" is still there - it's for compression loads in fuel,
combustion compression, and to a lesser extent thermal loads.
displacement "price" is less of an issue on turbo diesels.
but the good modern turbodiesels are really good. compare their
output/weight with some of the detroit v8's and you'll be pleasantly
further to that, all the "price" concerns tens to fade when considering
where diesels are going today:
note the trademark diesel high pressure injector lines.
I'm vaguely aware of the new high-performance diesels mostly in
Europe, I guess VW is offering at least one or two models here, anyone
Would they make a diesel-electric car any more practical - where the
diesel engine runs most of the time but just to turn a generator,
actual wheel drive is always 100% electric?
Or maybe drop one into a Volt?
in addition to the peugeot in that article [which would include citroen]
the bmw and mercedes high performance diesels are quite good.
but the majority of the action is in the smaller sector. they have
vehicle tax brackets in europe based on engine capacity. iirc, one of
them is for diesels below 2.0l. hence that's where there's most
attention. and why frod, g.m. and fiat all have euro-diesels that
qualify. [and why i get torqued that these "big three", who could for
ZERO DEVELOPMENT COST, OFF THE SHELF, won't bring them over here.]
you can lose efficiency doing that. it makes sense on a loco to get the
high torque from zero and to get transmission reliability, but for a
car, it's overkill.
the chinese component manufacturers of the volt wouldn't appreciate that.
A matched motor-generator is pretty efficient, and with solid-state
power electronics you can put a few batteries in the circuit and still
have systemic efficiency. And you gain more keeping the engine at
peak RPM - though I guess a CVT is helpful there too.
Still, it might be trendy, and more efficient than the Prius-style
hybridization. I suppose not cheaper, though. I still think from the
description the Fisker Karma may be 100% electric drive, but it ain't
right - batteries will be the essential differentiator.
the other thing is driveability. one of the things about the prius is
the starting of the gas engine, especially when pulling away from the
lights. while not terrible, i wouldn't exactly call it smooth. with
the compression of a diesel, that's going to be much more noticeable.
On 1/6/2013 12:51 PM, Stewart wrote:> depending on the delta between the two
Why not? My Civic hybrid is is approaching 11 years old (240,000 km)
and still giving good mileage. It has averaged ~46 MPG (US) or 5 L/100km)
over that time. I never expected to recoup the "hybrid premium" when
I bought it, but it has done better than than and paid off most
it not all of the luxury premium. (The 2013 Civic hybrid, was
fitted out with the fancy extras that came on the Acura EL).
yes, it is.
Just like the damn headrests that jab your chin down onto your chest,
although I think Honda took that particular federal mandate to a serious
extreme. On that alone, I wouldn't be another Honda.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.