Cars engines that 'turn off' when in stationary traffic

Are the emmission and cost savings these engines provide on a daily basis not outweighed by having to fit a new starter motor more regularly ?

75k and still on the original starter motor in my BMW..
mind you, it is the size you’d normally fit to an HGV, with a battery to suit.

I was wondering that. Our Golf has this feature and it does seem a good idea – I’m guessing that a different starter is used or maybe they’re just a lot better than they used to be.

They don’t have the same starting system as normal cars.

I have to laugh when people think they’ve uncovered a major flaw in something that teams of engineers have been working on for years after a few moments idle pondering in a traffic jam.

Freeagent – When they both die, have you had a look what the replacement costs are yet ?

Ive often thought that..

And?

I’ve no idea, but it means my company car is very, very cheap, so I’m happy…

Mol – I’m glad I provided you with a little laugh at this time in the morning. How does the ‘starting system’ differ from an f’ing big battery and electirc motor that engages with the engine ?

The stop / start I can live with as it doesn’t kick in often.

The electronic handbrake on the other hand. Such a non solution to a non problem I’ll not be buying another car with one.

Bigger, stronger, higher spec. How does a wind tunnel differ from a hair drier?

Mol – Ive never been in a wind tunnel, but I suppose they dont specifically heat up the air before blowing it. 😀

Bigger and stronger generally means more expensive (in money and environmental impact)to build and replace, which was kind of the point of raising the issue

Bigger and stronger generally means more expensive

Well you know the price of the car, take your pick.

I doubt that a slightly better engineered an rearranged electric motor (which are pretty simple components) is going to make much dent in the manufacturing footprint of a whole car – which is huge.

If you live in London or LA or somewhere else with massive traffic jams, it could save a hell of a lot in purely wasted fuel though.

Stop/start technology is just another last-gasp attempt to prolong the insistance on petrol engines before the motor industry admits internal combustion is out-of-date technology, and they should stop flogging a dying horse, fingers in ears going “la-la-la-la-la-I-can’t-hear-you” & wasting everyone’s time and just concentrate all their efforts on making electric vehicles

😀

If you live in London or LA or somewhere else with massive traffic jams, it could save a hell of a lot in purely wasted fuel though.

If you live in London or LA or somewhere else with massive traffic jams, why on earth do you still insist on driving a car ????!!

Freeagent – When they both die, have you had a look what the replacement costs are yet ?

No idea – it is a company car that’ll be off to the auctions when it gets to 4 years old…

Bigger, stronger, higher spec.

I have to laugh when something that teams of engineers have been working years on can be summed up by a knowitall forumite as being bigger, stronger and a higher spec.

Have a look here:

http://singletrackworld.com/forum/topic/truth-or-myth-whats-the-science

Mol – Ive never been in a wind tunnel, but I suppose they dont specifically heat up the air before blowing it.

Quite. some of them actually cool the air.

http://en.wikipedia.org/wiki/European_transonic_wind_tunnel

£40 per year tax 🙂

Seems to work fine on my Passat, and I can still beat most dozy drivers off the line 🙂

And auto handbrake is ace, I wish it had an auto gear box too, and adaptive cruise control, then it would be a truly amazing car instead of just great for shleping around the country in.

Not being an engineer, or a mechanic, but being on STW, I’m perfectly qualified to comment.

I would not be surprised, if it WAS less economical and rather a product that has been created to generate a perceived need, rather than meet a demand.

Mine counts how many seconds it’s been ‘off’ for. There has to be a point at which the engine being off becomes an economical saving, but funnily enough there is no mention of what that is anywhere in the literature (yes, I did look!).

Plus, I manage to unintentionally trick mine a few times a week where the engine shouldn’t be off and I find myself pumping the damned clutch to get it to start again.

I’m more impressed that all the other functions (power steering etc) continue to work. How much power does that take?!

We had an old (B Suffix) Polo that did this. Worked a treat, though it used to eat batteries in the winter.

[Quote]I have to laugh when people think they’ve uncovered a major flaw in something that teams of engineers have been working on for years after a few moments idle pondering in a traffic jam.[/quote]

Oh the ironing ….. Had to be you that wrote that mol.

Made my morning …… ( its only 4 am so its the first thing ive found amusing today. )

Stop/start technology is just another last-gasp attempt to prolong the insistance on petrol engines before the motor industry admits internal combustion is out-of-date technology, and they should stop flogging a dying horse, fingers in ears going “la-la-la-la-la-I-can’t-hear-you” & wasting everyone’s time and just concentrate all their efforts on making electric vehicles

Eh, stop-start has been in cars for years – or am I the only one old enough to remember the VW Formel E cars?

As for electric, I don’t think anyone is not concentrating on it, as the company that makes the breakthrough (range vs charge-time) will be ‘made’.

The electronic handbrake on the other hand. Such a non solution to a non problem I’ll not be buying another car with one.

We turned down a passat for this reason…

There has to be a point at which the engine being off becomes an economical saving, but funnily enough there is no mention of what that is anywhere in the literature (yes, I did look!).

I’m sure I’ve read that after 5 seconds of idling, you will save fuel by turning the engine off.
My 52 plate banger Astra has auto* stop-start.

DrP

*By auto, I mean, manual. Me.

(B Suffix) Polo

Polob?

I have to laugh when something that teams of engineers have been working years on can be summed up by a knowitall forumite as being bigger, stronger and a higher spec

The OP alleged all starters and batteries were the same. I suggested (simply) a few ways that they possibly could differ.

Using the starter for stop start system is noisy and slow to re start , psa use a 3 phase altanator , restarts silently , much better and quieter !!! @ £500 optional extra

If you live in London or LA or somewhere else with massive traffic jams, why on earth do you still insist on driving a car ????!

Ever been to LA?

My stop-start doesn’t work until the engine has warmed up properly, and doesn’t work at all if the temp is below 4 degrees. It also re-starts the engine automatically in the summer if the cabin is getting too hot, so it can put the air-con back on.

Clever eh!

Also, there could be good use of a flywheel type thing, thus not relying on an electric motor so much.

My 52 plate banger Astra has a KERS/boost system*, similar to formula one cars, that gives it a boost of speed.

DrP

*By KERS system, I mean an accelerator.

molgrips – Member

I have to laugh when people think they’ve uncovered a major flaw in something that teams of engineers have been working on for years after a few moments idle pondering in a traffic jam.

I have to laugh when people blindly accept everything presented to them.
You’re probably the type to pay extra for “long life oil”, or maybe you go to church.

Questioning things is the product of a healthy mind, and doesn’t make you a tin foil hat wearer, or an idiot.

The OP alleged all starters and batteries were the same. I suggested (simply) a few ways that they possibly could differ.

No he didn’t

Wow, this is all new to me, I simply thought they’d dumbed down the driving test so much that stalling the engine at lights / junctions / traffic has become normal behaviour.

DrP’s car is teh awesum 🙂

My midget had it and that’s from the 70’s.

Well it had half, I set the idle badly and the carbs weren’t ballanced so it would stall when you came to a stop.

I have to laugh when people blindly accept everything presented to them.

Lol.. you’re accusing me of this! 🙂

My original point was to do exactly as you suggest and think a bit more about the subject.

Cars are very reliable in general, and compared to even 20 years ago. Almost all the time you get in, and a complicated machines starts up first time. It’s big business, and they employ a lot of people to design the smallest details of their cars to achieve this.

So it seems unlikely that they’d just use the normal starter motor for the start/stop function, if it was going to fail all over the place. My point is that you should not assume that the starter motor is going to fail more often than any other component simply because it gets used more. It may turn out to be true, I don’t know, but I think it extremely unlikely that they would not have considered this.

You’re probably the type to pay extra for “long life oil”, or maybe you go to church.

um, well Oil, like fuel comes in all sorts of guises, some better, some not so much. Those that are generally more expensive are “that much better” and will generally last longer given the ocndiotions they work in at the performance they are supposed to. I can happily explain if you wish…?

Unsure – but I am getting 48mpg generally in town traffic in a car that does 0-60 in 7sec. I am not grumbling!

Cars are very reliable in general, and compared to even 20 years ago. Almost all the time you get in, and a complicated machines starts up first time. It’s big business, and they employ a lot of people to design the smallest details of their cars to achieve this.

So it seems unlikely that they’d just use the normal starter motor for the start/stop function, if it was going to fail all over the place. My point is that you should not assume that the starter motor is going to fail more often than any other component simply because it gets used more. It may turn out to be true, I don’t know, but I think it extremely unlikely that they would not have considered this.

I drive one of the most reliable cars ever made, and it happens to be nearing twenty years old.
But here are three words to counter your thinking:
Dual mass flywheels.

Check and mate. 😉

I’ve worked in manufacturing for most of my adult life, and have made a not inconsiderable number of parts for the automotive industry.
It may surprise you to learn that the life expectancy of cars is actually decreasing, and there is more money to be made in supplying replacement parts than there is in the original sale of cars.

Sui – Member

um, well Oil, like fuel comes in all sorts of guises, some better, some not so much. Those that are generally more expensive are “that much better” and will generally last longer given the ocndiotions they work in at the performance they are supposed to. I can happily explain if you wish…?

Yes, please explain how the long life oils will out perform the ester based Silkolene Pro-S 5w-40 that I run in my Datsun.
I suppose you could reduce the shear effect on the carbon chains by decreasing the difference between the winter and normal ratings of the oil, but then you’d end up with an oil that either wouldn’t lubricate the engine when cold as efficiently or one that would fail to protect at the upper limits of the engines operating temperatures.
Over to you…

I’m more impressed that all the other functions (power steering etc) continue to work. How much power does that take?!

Well, being as you’re not moving you won’t be needing the steering I imagine. And even if you did it could be run electronically. As could every other function in the car…. 🙂

You’re probably the type to pay extra for “long life oil”,

I use long life spec oil because my Passat is on long life service intervals and I believe it is required. It saves money at any rate cos I get 18k between services. Don’t think it costs me much extra at the garage though.