What's the consensus on this?

1) Drive away immediately so that engine is revving/under load

2) Idle on driveway for a bit

I understand that driving immediately will load the engine, but also there is very cold airflow over

the radiator!

If idling on a driveway the radiator is not getting cooled?

Probably a pointless discussion but what the hell!

Edited 17 October, 201213 yr by ItalianJob

I think its widely accepted that driving away immediately is best, but do not over-rev or load the engine until the oil is up to operating temperature.

Sometimes you have no coice but to warm it up. I find if i get into the car and drive off straight away it just steams up until the heating gets warm. Even driving with all the windows down the interior mirror and back window get steamed up

I let mine idle for a couple of minuets, to let oil get round then drive off.

It's worth pointing out that tick over engine speed probably isn't high enough to keep a battery charged - particularly an old battery or one having the extra winter load of lights, heaters, AC etc.

IMHO It would be better to drive off straight away and keep the battery fully charged.

The thermostat stops water flow to the rad until the engine is warm so cold air flowing over it makes no difference.

I always tick over for no longer than 30 seconds enough to get oil through channels, then drive gently until at running temp. I believe putting them under a light load quite quick is a good thing

I didn't know that the water flow was controlled.

Makes sense to drive off ASAP.

Interesting discussion, thanks.

On a frosty morning I usually start the engine put heater on max. and blowing up the screen - then set about scraping the ice of the side windows in the vain hope that the windscreen will then have started to clear form the heater.

My question now though is what would this do the DPF on my 1.6TDi CR?

This information is off this forum and explains what your oil does on cold starting and why you should warm up the engine properly.

http://www.briskoda.net/forums/topic/90661-16-important-oil-questions-answered/

12) Does oil have to be warm to do its job properly? Is it important to warm up your engine before using at speed?

Yes, it does have to be at least warm, and preferably hot. Most people except the sort with white finger syndrome find metal at 60C too hot to touch, yet 60C is too cold for oil in an engine that’s going flat-out. The best approach is to use a good 5W/40 or even a 10W/40, and take it easy for the first couple of miles, especially in very cold weather.

For racing, a really good warm-up is essential, except perhaps with special 0W/20 low-drag race oils. The trouble is, oil pumps are very good at pushing oil out at 60PSI, but unfortunately there is only 14PSI (atmospheric pressure) pushing it in! (Even less in Katmandhu.) So it’s easy for an oil pump to pull voids or pockets of vacuum in the oil if it doesn’t flow fast enough into to uptake. This ‘cavitation’ obviously reduces the amount of oil the pump can deliver.

Also, in high-speed bearings the oil can be too thick to keep up with the high rubbing speeds reached in modern engines so the ‘wedge’ or hydrodynamic’ effect breaks down. I know it goes against common sense (whatever that is) but the faster a bearing is turning the thinner the oil should be. (A 4cm. diameter main bearing is rubbing its shells at 56 MPH at 12,000RPM! To avoid cavitation the oil need to be less 10cSt or less, which is SAE 30 if the oil happens to be at 100C, or SAE 40 if its at 110C.))

What is the difference between road and racing oils?

The days of incense-like ‘R’ oils for racing only are past, except for classics. At least as far as 4-strokes are concerned, the best synthetic types are ideal for both race and road use.

With ultra-precise components, high-pressure pumps and high engine RPM there has been a move to special synthetic low cavitation/low drag oils to release more power with no reliability loss. These can be (and are!) used in road cars, but 0W/20 is not mentioned in the user handbooks, so there is always some warranty risk. Honda is perhaps the only exception!

It may not help dpf if not followed by a decent run. what I do is stick a fan heater in my car 10 mins before I leave then she is toasty and ready to go when I am, and usually dry on screen and roof etc too

Depends, if its cold then i have no option but to sit for the windows to clear, in the summer then i just drive off normally and keep revs to 2000rpm until engine is warm then increase it slightly, then when lovely and warm thrash the nuts off it... now and again.

It's worth remembering that your oil will take quite a bit longer to get up to a decent temperature e.g. Coolant warm up for me on my CR140 TDI is 3-4 miles but oil warm up is 8-10 miles

Sent from my Xperia S using TapaTalk 2

Read the manual.

It specifically warns you not to let the car idle from cold and to drive off as soon as possible.

Read the manual.

It specifically warns you not to let the car idle from cold and to drive off as soon as possible.

Exactly. The engine will warm very slowly at idle so what you are actually doing is increasing the time that to engine is running cold for......

Exactly. The engine will warm very slowly at idle so what you are actually doing is increasing the time that to engine is running cold for......

Bingo. Even worse if it's a diesel. My CR VRS needs more than a 12km shop run (crawling speeds, max 50km/h) to warm up properly. And it's only around 5C outside, not cold yet However I find the "extra oven" a nice feature, basically starts to blow warm(ish) air immediately after starting the engine. As for steamy windows - climate control works wonders.

Read the manual.

It specifically warns you not to let the car idle from cold and to drive off as soon as possible.

It only says this as a 'nod' to the environment, it even has the little flower logo next to it, like an eco friendly tip.

I always let i car idle for a to up 3 min depending on the outside temp. Your doing it absolutely no harm by letting it idle and anyone who says otherwise is just an idiot

You'll waste a lot of expensive fuel letting your car idle from cold for several minutes.

That's why manufacturers fit "stop/start" to their vehicles.

quick edit: Yes I do know that stop/start doesn't work when the engine's cold.

Watch your MPG1 figure drop if you're stuck idling in traffic for an extended period. :wonder:

A little bit off-topic perhaps, but here in Scandinavia many cars are equipped with additional heaters. It is more and more popular with fuel based heaters (Webasto or Eberspächer), but these are rather expensive.

Another alternative is a mains powered system, most popular here in Norway is DEFA:

http://www.defa.com/...omotive/warmup/

It's a modular system, and they offer engine heating, interior heating and battery chargers. I had this kind of equipment on all of my cars so far. It is making it possible to actually start a diesel engine when it is -35 deg. C.

Preheating saves fuel and wear on the engine, and if you have an interior heater as well you do not need to scrape ice anymore.

Of course you will need a mains power outlet close to your car...

myran

Start engine and drive off, with full electrical loading of heated screen(s), blower on full, dipped lights etc etc.

I never rev excessively though, but get the engine working.

Took the 1.9TDI in the Galaxy to 250,000 plus miles on this regime with any attention other than a service every 10,000 miles.

Engine still running like a clock when the old girl was parked up.

Simples

PS I have the luxury of keeping the car parked below a roof so my windscreen never ices up.

If iced up in a car park, need to sit and warm her up, with elevated revs after the initial start-up.

Edited 18 October, 201213 yr by dieseldogg

I think we're all worrying about nothing. Modern oils work very well even in our UK winter temperatures. For the oil there isn't a massive difference (but there is one, I accept) between +10 and -10 degrees C. Start it up, give it a moment or two and drive away.

For our Scandinavian chums there is obviously more of a problem

Drive it straight away but drive it sympathetically until the temps are up.

When I had a bike I had to warm that up first or the bugger would conk out changing gear in the cold. Carb icing was fun too.

....so if I'm not driving off right away then I'm somehow killing the engine? Rubbish - if that was true I'd be pretty screwed when the windscreen needs defrosted over the next couple of winter type months. Drive off as soon as is reasonably possible should be the advice!

It's not great for the top end of the engine to leave it idling away for too long, especially when cold.

To be honest, start it, don't idle it and if you don't like being super cold, then a mains powered or 12V powered heater isn't a bad idea.

There is a company that does a 12V powered heater. If you wire it in such that it's only running when the alternator is, then you can start eh car, drive off and have the oil and so car heating up to temperature much more quickly.

What's the consensus on this?

1) Drive away immediately so that engine is revving/under load

2) Idle on driveway for a bit

I understand that driving immediately will load the engine, but also there is very cold airflow over

the radiator!

If idling on a driveway the radiator is not getting cooled?

Probably a pointless discussion but what the hell!

Any cold air going through the radiator is doing nothing. When the engine is cold the thermostat diverts the flow away from the radiator to speed up warming.

Best thing is to start the engine as soon as you get in the car. Allow a few seconds for it to tickover to give the oil chance to circulate - while you fasten your seatbelt and get comfortable is long enough!

Don't redline a cold engine - wait until it gets up to temperature. My maxidot shows oil temperature and it lags a long way beihind water temperature. I don't give it any welly until the oil is over 70C - usually takes 4-5miles.