max revs for cold engine??
 

The place I work is right off a two lane highway with a speed limit of 65 mph. But most people drive about 75 or so.

So, especially on Friday's, i feel like quite the slow poke as I cruise at about 65 or 2800 rpm, until the oil is up to normal temp.

So, just curious, what is the max recommended engine speed when cold? I use the mobil 1 V-twin 20w50 in my 89 Carrera 3.2. Thanks guys.

some said 3k, some said 4k max. I do around 3k most of the time, sometimes 3.5k

I try to keep mine 3k or so.

I redline it after idling for 3 minutes (I live next to a highway) so I have an excuse for 3.6 conversion.. lol

I slowly bring it up to 4K max then cruise at 3K for about 5 miles or so.

Keep in mind that outside temps have a lot of influence on engine temp... Aircooled, so the colder it is, the better it cools, but also the longer it needs to warm up.

5 miles ain't much to warm up 10-12 liters of oil, at least it ain't in average weather, definately not enough in really cold weather. Hot summer weather , yeah, 5 miles will do .

Use the oil temp and pressure gauges to determine how long is enough.

temp will go up, obviously, and pressure will go down when the oil is hot. especially at idle...

I'm with the 3K club, until the temp gauge hits the first click...after that, the red line's the limit

3K here, also,..at least until I see 150 degrees,..then she's allowed 3500-3800....Once she sees ~180 (seasonal, of course), it's time to drive her like she likes to be driven'.....

Best,

Doyle

In the owner's manual for my 2004 996, it says that the RPM should be kept below 4,000 RPM until the engine is warmed up.

larry

1983 SC manual says keep below 3K until oil temp is out of the lower white area on gauge.

It does take a lot of discipline to keep at or below 3k rpm, doesn't it? Thanks guys. I figured that about half redline would be OK.

Also keep in mind the transmission/diff is also cold. keep shifts slow and smooth, let it gently go into gear and shift at that 3-4k mark and she should last a lifetime, use the right weight oil also. Brush your teeth, stay off drugs, check air pressure. There you go, life lesson #3.

Don't forget that lugging a motor is as bad as high revs when its cold.

+1 on the lugging. I usually run mine up to about 3,500 in 1st and 2nd gear using light throttle application. Then I try to keep throttle at less than 50% until the temp gauge clears the fat line at the bottom.

Not arguing, but can someone please explain why lugging when cold is bad? I know it puts additional stress on the engine, but is it not worse to rev it at 3K or so right after the engine is fired? My pea sized brain says its best to keep it under 2K for the first 5 minutes, regardless if I have to lug it, and once oil is warmed up and gotten to where it needs to go, then accelerate more briskly. Again, just trying to understand the whole concept of warmup (not stationary, which I believe has been known to be the worst due to possible carbon deposits) versus driving it and warming it up as soon as possible (some say the quicker the engine warms, the better MPG you get, but I rather have reliability on the engine and MPG secondary).

Has anyone seen an engine builder worry about revving up to 4K?(when the outside temp isn't balls cold)

I usually stay around 3K but can't think of a good reason why 4K or 5K would be bad. Any real world evidence out there?

When oil pressure reaches maximum (around 3000 rpm on cold engine) that is the maximum oil flow through the engine. As the oil pump increases speed, the extra oil is dumped through the PSV, and there will be the same oil flow at 3000 rpm as at 6000 rpm. Not good.

So yes, it is important to limit rpms when cold and the oil pressure gauge is the indicator. Thinner oil helps for cold starts ensuring sufficient oil volume pumped but must not be too thin with engine at full temperature

I may go as high as 3500 and keep the load off of it. Load is another thing to keep an eye on, flooring it at 3000 really won't be that great either.

George

Somewhere between 3-4K is fine but never lug the engine. But the other part to this question is engine load, this is much more important to understand. Do not apply much load on the engine while cold, for example going up a steep hill at 2500RPM with throttle 3/4 down is far worse than 4000RPM throttle 1/4 down. The reason for this is that as load increases so do cylinder pressures and in a cold engine it's these high cyl pressures that will cause issues. So just use common sense and don't lug engine and avoid medium to high loads till it gets warmed up.