30 seconds running before switch off?

Page 1 / 2
brucet3, Jan 15, 7:56pm
My grandson tells me it is best practice to run your car in neutral for 30 seconds before switching off . Does heknow something I dont know!

patiki1, Jan 15, 8:08pm
Yes,he has just bought some shares in BP.

jason18, Jan 15, 8:51pm
lol. Dont do that. Just a wasteof gas

bellky, Jan 15, 8:57pm
i don't know - is it a turbo!

intrade, Jan 15, 9:22pm
this is only for turbocharged engines. all other shutdown without running after. a divise called turbo-timer can do the running befor it stops.

sw20, Jan 15, 9:28pm
Even turbocharged engines from the 90s don't even need to be 'cooled' down. The majority of them are water cooled as well as oil cooled.

rsr72, Jan 15, 9:45pm
#6- Yep, and even before then. No manufacturer has ever seen the need to fit them.

phillip.weston, Jan 15, 9:55pm
but early turbo applications DID suffer from oil coking due to insufficient cooling down. but that was more to do with the oil available at the time not being able to cope with sitting in the hot turbo core when the engine was shut down with no oil flow.

sfw4, Jan 15, 10:37pm
other way round. run engine for atleast 1min before taking off in morning. the amount of people taking off full ahead from very first start. geesh!

NZTools, Jan 15, 10:43pm
Once again, that may have been good practice 30 years ago, however the engines of today are designed to be started and driven straight away. (albeit not thrashed)

Leaving them to idle when cold will cause more engine wear than getting them up to operating temperature quickly by heading off down the road.

rayzor14, Jan 15, 11:36pm
That is a matter for debate. Ball bearing turbos, despite being far more advanced still spin at a hell of a rate. Particularly in open road or high throttle use just prior to shut down you have a device spinning at huge speed that instantly has oil pressure and water feed removed. Over time there result can only be premature failure.

sw20, Jan 16, 12:12am
If you go from full boost to stopped in a matter of seconds you must drive like a retard.

sfw4, Jan 16, 12:18am
you gotta be joking me! but yes this is standard practise from 30years ago, old skool to warm up engine before doing 4000revs down the road. i beleive some big Diesels cummings etc can be driven off straight away

rayzor14, Jan 16, 12:24am
Nobody mentioned full boost. Just imagine people in the country - 100kph, slow down, turn in the drive and stop.
Or me just tonight, towing a large trailer, up the drive and stop.
Both of those will see high RPM in a turbo and do not in my view represent anything abnormal in terms of driving.
I think the point I am making is that there are actually uses for turbo cars other than simply going fast. Many of those uses (towing with an XR6T for example) translate to relatively low road speed with comparitively high turbo rpm. To me that is simply using the car as it was intended.

pettal, Jan 16, 1:16am
Just do what the Yanks seem to do in the movies and on TV= give the gas pedal a good pump just milliseconds befor you shut it down,, of course it sounds better when you do it to a V8 .

loonee-dial-111, Jan 16, 1:54am
Stock turbo = not required or it would be built into the car.

mark.52, Jan 16, 3:28am
I run the car at idle for a few seconds before shut-down, or until just after the radiator fan has turned off if it was on.

If it's good enough to do this for an aircraft piston engine, to let the "hot spots" (which might include the turbo blades) even-out, it's good enough for my car.

I also let it warm at idle for as long as it takes to plug the belt in, adjust the mirrors etc, then drive it fairly gently till the temperature comes up toward normal.

This will do no harm, and may do some good. Sure, water cooled engines aren't prone to having the same order of "hot-spots" as an air-cooled aircraft engine, but they still have them. Depends how it has been driven in the minute or two before parking the car.

primemeat, Jan 16, 6:14pm
The manual for my 97 Prado said to let it cool down for 30secs around town and 60secs when been on open road.

sifty, Jan 16, 7:32pm
I turn mine off 30 seconds before I park. I like the element of surprise when sneaking up on people, and the loss of steering gives a good workout.

scuba, Jan 16, 7:56pm
could be very surprising on corners

bob1088, Jan 16, 9:57pm
not a bad practice for turbo vehicles IMO and also for older cars some of which have carbon deposits in the combusion chamber which may still be glowing red hot and causing run-on. Idling for a short time allows these areas to cool and usually prevents run-on. Older cars probably benefit from warm-up before moving off, but, as already mentioned, not newer ones.

bob1088, Jan 16, 9:58pm
RX7 I had - was imperitive to warm up and idle down.

m16d, Jan 16, 11:40pm
Your grandson is correct.Nothing wrong with a few seconds "Warm down" before you switch off.

chris_051, Jan 17, 12:11am
Apart from Cat/Cummins in on highway trucks.
In saying that you gotta laugh at these wankers in jappas who pop down to the shops or pull up at the beach and let her sit there idling for a couple of minutes on the timer before shutting off.
Even with water cooled ones after a good work out I wouldn't turn off for a few minutes, such as pulling 40 tonne up the Bombays then stopping in at BP truckstop. As for cars unless theres a trackday you'd struggle to put one under a similar level of load so not such a major.

richardmayes, Jan 17, 12:47am
Car makers are also motivated to keep the price of their cars competitive. A factory turbo timer mightincrease the price of the new car by a greater amount than what it costs you to buy one (uninstalled) at ripco.And a turbo timer benefits the second or third owner of the car; why would the manufacturer care about him, he isn't paying their wages.