On a vehicle where it's been designed to do it is one thing, all the various components will be designed to cope with the constant restarting, plus they have sensors/brains to detect when to not do it and let things recover.
Do you kill the ignition when stopped for a prolonged duration while waiting at traffic lights, junctions, etc?
Not sure I would trust it to always restart myself.On a vehicle where it's been designed to do it is one thing, all the various components will be designed to cope with the constant restarting, plus they have sensors/brains to detect when to not do it and let things recover.I'll stick to letting it idle.
SWMBO has recently swapped her convertible Saab 9-3 for a Golf TDI DSG. We have manual Skoda Octavias at work with the same stop/start technology. Makes much more sense in the DSG car IMHO, vs the manual it seems clunky, annoying and just doesn't seem to work well with the gearbox. At work I turn stop/start off, driving her car I let it do its thing. On the bike, I'd kill it if I knew I'd be waiting ages; there's a level crossing just off the A59 near Airedale Hospital where you can sometimes be held for three trains in a row, I usually kill the engine (after filtering to the front of the queue) if I'm held at that crossing. For me it comes down to local knowledge; if I know I'm going to be held for a good while at a specific obstruction I'll turn the engine off, more so in hotter weather. Other than that I'd leave her idling, I feel I'd be hammering the starter motor, battery and alternator etc. doing much more work than it wasn't designed to do, i'd rather pay for a few pence more of petrol than several pounds for battery/alternator/starter motor work[size=78%].[/size]
For many years I've heard that most (80%) of the wear and damage in an engine occurs during start-up and shit down.On shut-down, the very thin oil film over bearing surfaces etc stops being "circulated" and sits there between 2 extremely hot metal surfaces which don't have fresh oil replacing that in place, to cool them - it carbonises and loses it lubricating properties and leaves a deposit on the bearing surface that is not a lubricant.On start-up, bearings and other engine surfaces, run with less than optimal oil coverage/oil pressure and so additional wear occurs.I'm sure that hasn't changed, but maybe the make-up of oils has changed so that it's no longer the issue it used to be, but being an old Luddite, all I can see these stop-start systems systems doing is causing extra wear/damage to the engine.I'm sure the only reason they were developed was so that car engines would automatically shut off during the laboratory testing process to determine the emissions levels for compliance reporting and vehicle approval (basically it was a "cheat" just like the VW cheat, but only adopted by every manufacturer), with no real-world benefit or relevance. But now that it's been adopted though, it can't be dropped unless the testing process is changed, otherwise all the cars would fail to comply in the "lab-based testing" !!
For many years I've heard that most (80%) of the wear and damage in an engine occurs during start-up and shut down.
Quote from: Millietant on 04 July 2019, 03:52:07 pmFor many years I've heard that most (80%) of the wear and damage in an engine occurs during start-up and shut down.I could see that for starting from cold, but I'd have thought that, for a warm start, it wouldn't be an issue.