CGTS warm up time

[Rockster]

benny 61 said:

Why can't you warm the engine up just idling? I'm well aware you shouldn't but why not.

You can. Oftentimes when I have my cars in for service the techs let the engine idle until it is up to the oil change temperature. (I have data/tracking devices in both my cars and in some cases can observe the vehicle's activity when it is in the dealer's service bay.)

However, unless you are preparing to change the oil it is not advisable to let the engine idle too long. Mainly it is wasteful and the engines emit considerable pollution at this time although the engine controller is designed to try to minimize this.

There is minimal, make that zilch wear. Honestly. Both of my cars have spent considerable time idling from cold -- after of course being started from cold -- and both engines are just fine. One with 294K miles the other with 137K miles.

While I'm a firm believer in getting the engine warmed up some before driving off I do not let either engine idle to full warm up. My "timer" is I let the engine idle until the high cold idle speed drops to near normal and in the case of my Boxster the secondary air injection pump shuts off. (I can't hear this in my Turbo.)

Unless it is real cold the above takes less than a minute. I have found over the years both cars are more tractable, easier to drive smoothly, after a bit of idle time.

Once I'm underway I keep RPM's below 4K and probably closer to 3.5K or a bit less until the engine has been up to temperature for a while. I know from direct observation both in real time and in viewing this data afterwards both engines can take a long time to reach operating temperature. We are talking sometimes 10+ minutes or more and this at something above engine idle speed.

[bcr5784]

anonymous said:

[redacted]

Accepting that they might be unconcerned about long term unreliability consider that

a) Both tracks were all- but empty on my day
b) There are miles of little used perimeter roads at Silverstone
c) They might be open to criticism if they did not do what Pork manuals (and common view) would regard as sensible.

Could it be that (with modern oils at middling ambient temperatures) the need to adhere to such warm up procedures is perhaps overstated? Much as the running in procedures have become much more vague.

[BertBert]

And we are still speculating as to whether the advice not to idle is based on engine wear or not I believe.
Bert

[simond39]

As per OP, I've also noticed the warm up time on my new CGTS is a lot longer than my previous 987.2 CS. Any thoughts on why this is? On my old non digital gauge, it would be up to about half way or normal operating temperature after about 5 minutes of idling or gentle running below 3K revs but now takes more like 10 to 15 minutes. Is it just a case of TADTS

[Rockster]

anonymous said:

[redacted]

It is about emissions and fuel consumption. All car makers who face either EU or USA emissions/fuel economy tests will always state no warm up. Start the engine and drive off as soon as possible. Porsche (and this is probably true of other car makers) inserts a caution to avoid high RPMs until the engine is fully warmed up but emission/fuel consumption tests do not AFAIK venture too high in the engine's RPM range.

Partially this is enforced by those cars with automatic transmissions that have a shift map that grabs the next highest gear at very low RPMs.

This "no warm up needed" policy is to ensure when the cars are being tested for emissions and economy the tester doesn't let the engine warm up any and make the test results worse.