Tell me about the Honda Insight

Malc · 19 Jan 2011 at 18:20

I always thought that hybrids were efficient when running from the battery due to them having a small combustion engine running at its most efficient revs charging the battery.

On a motorway the engine can't charge the battery at a quick enough rate and therefore the car starts to run purely from the engine. As it's small and no longer constantly running at its most efficient revs, the car loses MPG.

Jonnycoupe · 19 Jan 2011 at 18:29

As its not a perpetual motion machine it does nothing of the sort. Very few hybrids have an EV mode capable of motorway speed. Instead they just drive like a normal car but instead of opening larger cylinders when power is required they can assist with a grunt of electric torque. It can then trickle charge back up or later as you leave motorway.

Running directly from the engine will always be more efficient than any sort of EV storage and reuse. See Chevy Volt for case in point. As they are CVT the rpm point can be whatever it wants but of course different loads at the same rpm can be different efficiency in terms of energy from the fuel, so its all about playing tunes with that aswell as driving to predict whats actually happening ahead. Hybrids with GPS systems for route planning would help massively in this respect.

Jez · 19 Jan 2011 at 18:32

Jonnycoupe said:
I wish my normal Focus did 44mpg!

Well, mine does more than that actually! Ive just worked the numbers fairly accurately (it doesnt have a computer, but i remember brimming it again at a cost of £52)

Tank Brimmed
Mileage covered = 4*110=440 miles (8 trips, 55 miles each way to work, 4 days)
Fuel used = £52, @ 5.55 per gallon thats 9.37 gallons (guess on price, may be slightly off

Consumption = 47mpg.

I drive very economically though, thats as good as it will likely ever get. My S-Class which i usually use is most economical on this route of any i do.

Jonnycoupe · 19 Jan 2011 at 18:43

Thats combined use by Dorris and her short trips though, much different to your routine. Only managed 35 or so going to or from Cornwall. Mines an old 99 1.8 Zetec though, which is frankly arse. That said it also discredits my example to a certain extent as its an older engine.

Malc · 19 Jan 2011 at 18:52

Jonnycoupe said:
As its not a perpetual motion machine it does nothing of the sort. Very few hybrids have an EV mode capable of motorway speed. Instead they just drive like a normal car but instead of opening larger cylinders when power is required they can assist with a grunt of electric torque. It can then trickle charge back up or later as you leave motorway.

Running directly from the engine will always be more efficient than any sort of EV storage and reuse. See Chevy Volt for case in point. As they are CVT the rpm point can be whatever it wants but of course different loads at the same rpm can be different efficiency in terms of energy from the fuel, so its all about playing tunes with that aswell as driving to predict whats actually happening ahead. Hybrids with GPS systems for route planning would help massively in this respect.

I've just checked up and it turns out there is more than one type of hybrid setup. The one I was trying to describe and got slightly wrong (and the only one I thought existed!) was the Series Drivetrain. This config is less efficient on the motorway due to the normally constant speed engine having to vary its revs in order to power the car.

http://www.hybridcenter.org/hybrid-center-how-hybrid-cars-work-under-the-hood-2.html

Jonnycoupe · 19 Jan 2011 at 18:59

A series hybrid is not yet in production anywhere in the world.

The concept also revolves around the idea of the plug in hybrid aswell.

Malc · 19 Jan 2011 at 19:04

Yes I've just read that as well.

It all stems from earlier on in the year when I quickly thought "How do hybrids work" and just read a tiny bit of an article.

Lashout_UK · 19 Jan 2011 at 19:21

The Auris will only run on its battery for just over a mile in ideal conditions......I've had it down to a considerably less than that at night with the AC and lights on.

ghop · 19 Jan 2011 at 19:56

Jonnycoupe said:
Thats combined use by Dorris and her short trips though, much different to your routine. Only managed 35 or so going to or from Cornwall. Mines an old 99 1.8 Zetec though, which is frankly arse. That said it also discredits my example to a certain extent as its an older engine.

I have a '00 1.6 and managed 50mpg on a 230 miles each way run to wales + a few trips to a nearby town. The difference you'll see driving at around 60 rather than 70 is pretty awesome!