If you were concerned only about dry starts then you wouldn't use 10w30 (and that is what the manual will recommend).

I hope this thread has been somewhat informative, oil can be a hotly debated topic. Usually because people are quick to defend their service regimes as "something I've always done and never had a problem". That doesn't mean its the best thing to do.

If dry starts on the engine are your only single concern, then I would suggest a pre-lube pump just like slalom44 mentioned and use a good 0w30 oil. That will essentially prevent having to dry start your engine. The only reason I mentioned the transmission was to bring up the fact that the engine isn't the only lubricated device in the car that can experience a "dry start". This is why it's best to just drive the car gently while it warms up, this doesn't put any undue stress on the drivetrain components, engine included.

 

"This is why it's best to just drive the car gently while it warms up, this doesn't put any undue stress on the drivetrain components, engine included."

I agree that getting an engine to operating temp is important. That's why it would be a major hassle to start it and let it run every day or two. Also I keep a cover on it during the week.
Quick story. My office used to be just a few blocks from the house. Total running time was less than 10 minutes (each way). I rusted out the exhaust on a new Explorer and also on a F-150 both in less than a year. The exhaust never got hot enough to boil out the water, so basically all week long condensed water was standing in the pipe and muffler. I'm sure it took a toll on the engine too.

 

I agree with the don't start it every day crowd. The last thing you want to do is introduce fuel dilution into your oil. This phenomena will destroy even the best engine oils in a very short time. I drive my car similarly to how often you drive yours, and have similar aspirations to keep it for a very long time. Up until my last oil change, I've run 10W30 synthetics with 4-5K OCI's and the PCX-004 oil filter with absolutley no indication of abnormal bearing wear on 2 UOA's (at 15K and 30K). That being said and well documented in the UTH forum, I've decided to try Castrol Syntec 0W30 for a couple of fills. I'll do another UOA on the 0W30 after the second fill and try to give you an unbiased comparison of how it stacks up against the 10W30 UOA's. Stay tuned.
Bottom line...drive the 10W30 with confidence until either I or somebody else shows you evidence that it's not the best choice for the S2000.

 

Not to hijack this post but.....


So what exactly is fuel dilution?? Is it when your car sits idle too long?

Im glad to find out more and more stuff on here everyday

 

I agree with everything posted by 90crvtec. I'm assuming that he too lurks around BITOG where this type of information gets discussed a great deal.

If ChefJ were to post his suggestions over there, he would likely get ridiculed, harassed and possibly banned.

It is well known that 0W- and 5W- oils attain oil pressure faster during cold starts (yes, starts with a cold engine, even in hot weather) than 10W- oils. Since DeeDubya is letting his car sit for a week at a time, this is very important. I've read posts from several tribologists talking about this. I could search and post this to prove it, but I really don't want to waste my time proving something to a person who obviously doesn't know what he's talking about and apparently doesn't care.

When an engine is cold, it runs with a rich fuel mixture. Because it is rich, not all of the gas gets combusted in the cylinders. The non-combusted fuel mixes with the oil coating the cylinders, and eventually gets washed into the oilpan. When you are idling your car, your engine doesn't completely warm up, therefore a significant amount of fuel gets into the oil. If the car doesn't see a significant amount of highway miles, this fuel will stay in the oil and not vaporize and exit out the PCV valve. The primary problem with fuel dilution is that it thins out the oil, changing the viscosity from an xW-30 to an xW-20 or xW-10.

Fuel dilution is a common problem for "Soccer Moms", since they will often sit in their minivans with the engine idling watching or waiting for their kids. An idling engine doesn't get hot.

 

An idling engine doesn't get hot??

 

This post just keeps getting better and better.
The MAP is only rich for a few minutes at most and as the car comes to NOT it leans out. Sure the EGT's are only around 700 degrees as opposed to the 1200-1400 degrees of highway driving but the gasses are still exiting out of the PCV and back into the intake for recombustion.

 

You just explained why fuel dilution exists and is a problem for cars that idle constantly. Good job. That wasn't so bad, was it?

 

Lesson for 90crvtec: You'll never win an oil debate

About the gearbox: the oil pump only pumps when you are moving.
It doesn't matter if it is in gear, any gear.
If you are moving down hill, its allready pumping.
And.. at idle, in neutral, clutch out: only the primairy shaft is spinning, because 1st and 2nd are fixed on that shaft the 2 counter gears and reverse (thats's driven off 1st gear) are spining too.
The rest inside the gearbox is stationary at that point.
(and without fresh oil supply from the pump)

 

[QUOTE=ChefJ,Aug 13 2007, 07:41 AM]Start it daily.