http://www.goodcleantech.com/2008/03...us_in_mpgs.php

MikeyB

 

That was the headline on Yahoo's home page also...looks like someone is headed in the right direction.

 

I love it!

Man, I'd take that BMW anyday over the Prius. We're finally seeing what diesels can do.


John

 

I always thought the gas/hybrid technology was not really a good idea. An efficient diesel is definitely the way to go. The VW lupo gets around 78 mpg, mileage that Prius owners could only dream of. All with no hybrid junk to go wrong. I wonder how much study has been done into the long-term longevity of starting and shutting off an engine that much too. It just doesn't seem like the answer.

 

This brings to mind what I'd really like to see. I would like to know just what mpg is possible in a heavy duty truck platform while still being useful for what it was designed for. I'm convinced that manufacturers leave quite a bit on the table in terms of mpg because the truck market is simply not that interested in mileage. Truck buyers, for the most part, are interested in power (look at the advertising). I would love to see someone really look into max fuel economy by fine tuning the software and tweaking turbocharging strategies and remote lockout of the front drivetrain. I don't know how much is there but it has to be something.

 

This is all good but aren't the diesel VW's are doing 45 or better without the batteries or regenerative braking, just diesel.

 

Yes but the Jetta/Golf platform is significantly smaller than the BMW 5-er platform. The two noteworthy things about the BMW in the article are the MPG's, of course, and the size of the vehicle.

 

Problem is, the "Prius crowd" will puff up their chests and say, collectively "Yeah.... Well, our emissions are cleaner!" It's always about emissions when someone brings up just how much the Prius DOESNT live up to it's MPG claims.

 

Gas = 20-25mpg
Gas/Electric hybrid = 40mgp
Diesel = 40mpg
so...
Could a Diesel/Electric hybrid = 85-90mpg?

 

well not exactly ... hybrids are good for city driving ...starting and stopping and short trips while maintaing good mpg numbers. With highway driving, one has to consider the aerodynamic drag and rolling resistance as the two primary factors in mpg, diesel shines then. So if we're to use a diesel/hybird in a midsize car, I could see a 50 city/55 highway being possible, maybe more, but I don't think 80+mpg is sustainable with current technlogy.

With a plug-in diesel hybrid you may be able to see those 80mpg numbers on short trips, but on long trips you're fuel efficiency would be dependant on whatever the little diesel engine could deliver, since the electrical system would be tapped out without regenerative braking to recharge it.

 

Well...depends on the emission that you're measuring. If it's CO2, then the diesel would emit less becaue it not only burned less fuel, but also because diesel emits less CO2 than gasonline (if I'm not mistaken).

 

Certainly a little chip out of old Prius's block.

It would be interesting to see what a 120d with a 6-speed would do in the same test.

Too bad we will only be getting the 3.5L diesels when they arrive later this year, but at least it's a start.

 

Ok... Thanks...

New question... Gassers have used the "drop half the cylinders" technique for getting better MPG for years. In a non-tow/hauling application, cruising the interstate at a steady speed, you think it could be done in a diesel? or would it fail for similar reasons above?

Mechanicly it should be able to do it... Right?

Now take for example a VW Jetta... it gets 50+mgp already, apply that technology to it and highway mileage should drastically increase...

Does this make any sense?

 

I don't under stand all the hybrid b.s. I drove metros for 10 years got 50 mpg all the time and diesel rabbits before that and if the metro was still built I buy another one.The metro was far better then the VW.

 

just for reference, a 2000 insight registers a maximum of 0.1% co tail emissions at idle.