To most extent. I think it boils down to effeicency of transfering energy and practicallity of doing it. Also with ICE, what is the energy used to transport the gas or diesel to the car? If we are using that as a measure for electricity, then that needs to factor in for petrol. Maybe we do find deisel is the mmost effienceint.
To me the prospect of diesel is that of Bio fuel. I think it is the most promissing form of it, for transportation. Electricity from wind, hydro, solar is probably best used for residential and comercial HVAC and lighting, or stationary usage. At least presently.
Tom

Are you prepared to stick your hands in the combustion process? As difficult as that may be. Or go Tunisian?
Tom

Skinny tires cost lives. My 2 cents.

LOL QOD

[QUOTE=custom options such as wide or narrow tyres..[/QUOTE]

In my 603960 (6cyl turbo) the best I have achieved is 35mpg (american) but when I put on a set of bigger winter tyres, it dropped 10%. I was surprised as I was expecting the larger diameter tyre to give a small increase in mpg.
That said, the increased grip is worth far more than the cost, here in the sloppy snow of eastern Canada.

I enjoy what you're trying to say, but instead of sounding like a troll why don't you explain why his point is wrong.


The best part about diesel engines is how simple it is to make a compatible biofuel. I can't wait for the hemp industry in this country to take off and start using that as a source of biodiesel.

1. Starting a hot engine is real easy, easier still if the car is rolling. Which hits a battery harder? .5 seconds at 200 amps for a starter or a 10 second cycle of 10 amps for a cooling fan?
2. Full authority ECU's (push button start) make this more practical.
3. At idle, gas engines suck the air charge past a nearly closed throttle, doing significant back work. Diesels idle by governing down to idle stop or idle rpm w/ free flowing intake. Stop/start engines gain more w/ gas than diesel.
4. The benefit varies- you would see none on the thruway, but a lot in a traffic jam. Most people live in cities, most urban drivers know sitting in traffic.
5. Stop/start engines would also benefit air quality & reduce heat pollution where it sucks the most (well, due to cars)- next to jammed up urban traffic.

Then factor in the 80% efficiency of grid power distribution from power station to suburb, the 88% efficiency of the substation, the 85% efficiency of the local grid, the 88% efficiency of the local step down xformers, and the 90% efficiency of the last mile low voltage supply to the home (actual CEGB numbers) for an overall efficiency of 47%

Are you prepared to stick your hands on the 92 VDC terminals of a leccy/hybrid car battery bank?

like for like, it's a *****.

Larger diameter tire == Odometer offset.

I recently got 33.4 on a tank with 2 adults, 2 kids and the trunk full of wheels. Avgd ~80mph.

your point #5 is the ONLY reason it is done.

200 amperes x 12 volts = 2.4 kW, 2.4 kW for 10 seconds = 7 watt hours. BUT, you have to recharge the battery, between alternator and battery inefficiencies you are up to 30 watt hours.... this can ONLY come from energy that would otherwise be used to propel the car.

A diesel idling at (mb 300d) 0.6 litres an hour = 6.6 kW an hour = 110 watt hours for 1 minute idle.

If you work it out as 20 traffic light stops on a journey, each one for a full minute, you save around 2 kWh, or around a pint and a half of diesel.

but in the real world, your radio is running, your electric cooling fan may still be running, your heater / ac may still be running, and these are all sucking the battery down, so your real comparison is not 30 watt hours vs 110 watt hours per stop, but 60 or 90 watt hours vs 110, plus the increased wear and tear and load on starter, alternator, battery (only so many charge / discharge cycles in any battery) and suddenly it looks crap from an energy viewpoint.

Even emissions it only works if you ONLY measure emissions while waiting at the stop light.... you get MORE emissions on the way to the next stop light recharging the battery.

Good, now we are half way there. What's the efficiency of an ICE motor? I do agree with you assesment of efficencies of transforming from one voltage to the next. Still, you have to figure in the efficiency of transporting liquid, ie gas or diesel. Pipe lines do it fairly effiecently to a point. That is part of the problem with Ethanol. I don't think you can use the same pipe lines with certain types of fuel.
Tom

Also, he is essentially regearing the drive train. A lot of Jeeper have problems when the put on bigger tires, and don't regear the axle(s). Also, changing the gear in the speedometer cable. So, the gear train isn't set up to effieciently power the wheels. Motor bogs so it doesn't operate as efficiently.
Tom

10 seconds goes with the 10A cooling fan, not the 200 amp crank, I guessed .5 seconds, I doubt it takes that, it'll hit on the first power stroke, if it's hot.

The prius uses the gearbox to crank it's engine if it's moving. Quite a neat bit of controls, actually.

If it increases mileage, and you don't plug it in at the end of the day, I'm guessing it looks alright from an energy viewpoint.

The last rental car I had in Europe had this feature... Audi A4 2.0L TDI. Pretty neat and you could turn it off. WHen the motor was cold, the feature automatically was turned off. It wasn't till the motor warmed up did it automatically shut off when stopped for a more than a few seconds in neutral. Press the clutch and it immediately started up before you got it into first and off you went.

I don't doubt that all those additional starts put a strain on the starter, but in terms of the life of the vehicle... I don't think it would be a big deal.