In a post about the rev limiter kicking in early bmarshall made reference to a 4 mile rule. I've searched for this but can't find anything.

Brian - can you enlighten us?

- David

 

He means dont Vtec for 4 miles, The rev limiter kicks in early until youve got three bars on the temp guauge. Most people leave it a tadd longer before they Vtec, I personally build up slowly.

 

Yes I figured that was the case but any particular reason why 4 miles.

For example, what effect does ambient temperature have on the amount of time the engine takes to warm up?

And another question I was wondering about:

If you've been driving for a while but then stop for a short while - say less than 5 minutes/a petrol refill for example - is it ok to VTEC immediately on getting back into the car?

- David

 

4 miles in central London could easily be 1/2 an hour, I guess the 10 minute rule would be better.

Also if you live in California in the middle of summer you could apply imperial logic and have an 8 minute rule.

A combo of both 4 mile / 10 min are useful however as if you are going anywhere near VTEC, as you might want your tyres warm too!

 

It does indeed ensure tyre warmth and re: the ambient temperature. Sure it has a bearing but 4 miles is the datum. Even in hot times its better to be sure.

Me, I prefer a nice engine and no dented body panels. 4 miles isn`t much to suffer!

 

I thought everyone knew not to rev a cold engine?? As for when to start 'ragging' it, this will be down to common sense. If it's 0 degrees ambient then it'll take longer to warm up than if it's 20 degrees

 

Q.

I presume when talking about warming the engine up we really mean warming the engine oil up? Presumably once the oil is up to temp and has had a chance to circulate how much does it matter whether the engine innards are warmed up?

Or are there any issues with thermal expansion in engine components being warmed too quickly by going into , hence the need to warm up gradually?

Ta.

 

I always use the 10 minute rule.... see the previous post

 

[QUOTE]Originally posted by BigTed
[B]Q.

 

IIRC Brian was advising people to warm up the tyres as well as the engine. Hence four miles running.