STi

Hi,

MY first post so I'll introduce myself a bit. Used to own a Honda integra typer - first real sports car! Then went onto a Subaru wrx sti4. Ever since parting with the integra typer I've always missed that vtec buzz...Suffice to say I've just rectified that by buying a bright yellow S2000! Wow I never thought I could afford one of these!

Anyway back to the subject; having just done 3000 miles I think an oil change is called for. I called Honda up to find out what oil they use: Mobile1 15W40. I see most of you use 15W30, but I'm not sure what the W30 means...is it the relative thickness when the oil is hot ?

Lots of questions, but I gotta leave now and get some new speakers installed

Cheers, Mark

cthree

No the correct oil is 10W30. 30 is the thickness or weight of the oil. Too high and the oil won't flow to the small tolerance parts. 10w30 is what the owner's manual, service manual and Honda say to use.

STi

Thanks, so what does the 10W translate to ?

The Reverend

The first number refers to viscosity when cold and the second is when hot (something like that). Anyway, lower first number is better for cold, because the oil will be thinner and able to flow on cold start ups, instead of being all sludge-like. The higher the second number, the better your protection when hot because it wont get too thin on a hot day. Anyway, 10W30 should be fine. 5W30 is a little thinner and seems to give a hair more power according to my ass-dyno.

cdelena

Oil Viscosity

Important Facts about Oil Viscosity:

1) Engine Oil is available in different viscosity ratings. Viscosity refers to an oil's internal friction, resistance to flow, or adhesive characteristics.

2) Oils of different viscosity levels have been assigned numbers by the Society of Automotive Engineers. The lower the viscosity, the lower the assigned number. SAE 10 engine oil, for example, is recommended for cold weather operation and SAE 30 for warm weather. The SAE number of oil has nothing to do with its quality.

3) There are single-viscosity and multi-viscosity oils.
Single-viscosity oils are used in areas where the temperature is consistent. Multi-viscosity oils are used in areas where there are seasonal changes or extreme temperature differences between the morning and the evening

4) Examples of a multi-viscosity oil include 5W-20, 10W-30, 10W-40, and 20W-50. A low numeric viscosity is needed in cold weather, or the engine will have difficulty turning over due to the resistance of the thick oil. A high numeric viscosity oil is needed in hot weather, or the oil will thin and will not provide enough protection for the engine components.

5) In oil grades, a "W" stands for winter grades and means that the viscosity test was performed at at temperature of 0 degrees Fahrenheit (-18 degrees C).

6) Oil containers display a logo.
This logo provides the consumer or technician with the proper data concerning the type of oil in the container. With this information, the right grade of oil may be obtained for the appropriate weather and the specific engine application. Oil containers also contain a seal to ensure the purchaser that the oil meets the most current quality ratings

7) There are many different additives in existence today.
One of the first to be used was a pour point depressant. This additive eliminates concern for the occurrence of the following scenario: at low temperatures, the wax in the oil can crystallize and form a sort of "honeycomb" which blocks the flow of oil to the oil pump. Pour point depressants help prevent this from happening

These additives combine to produce an oil that will not only withstand heavier loads, reduce corrosion, and end foaming, but will also keep the interior of the engine cleaner and increase its useful life

cmnsnse

Ive read that a 5w30 Mobile One synthetic has been proven to free up some power because its easier to pump through the engine (thinner)

Like The Reverend said the broader the numer range the wider the temp range.

Without getting really into detail I would say that its bad to use the synthetic/thinner stuff untill the engine has some miles. Well, maybe not 'Bad' but not as good as using thicker oils at first.

STi

Thanks guys

I think I'll use either 10W30 or 15W40 for my first change since it gets pretty hot here normally.

I've heard of power looses/gains so I want to get the right oil. Mobile1 sounds like the best plan, anyone had good results with Redline?

Cheers

cmnsnse

I have been using Castrol Syntec but ummm, errr, have read that between Castrol and Mobile . . . only mobile showed a gain on the dyno.

Interesting that Mobile invented synthetic for jet engines,(because of the extreme temps) but wasnt the first to bring it to the automotive market, Amsoil was there.

I dont know a thing about Redline.

[Edited by cmnsnse on 02-15-2001 at 06:39 PM]

elviscos

what about additives like slick 50?

The Reverend

From what I have been told and what I have read from sources who seem to have a good understanding of the chemical engineering that goes into a high-quality oil, additives have no benefits and will often have negative effects - stay away from all of them.

Marco from Vegas asked me on IM what I prefer between Redline, Mobil 1, and Royal Purple. My answer was this - I don't know which is best and there aren't many people that really do, since it requires a deep understanding of chemistry, mechanical engineering, and all kinds of other sh!t that no one has the time to learn unless it's their job to do so. BUT, I use Mobil 1 because I know that it's all very complicated and I know that Mobil has the biggest budget between the three. So I reason that their resources lead to the best product. I could definitely be wrong, but if Mobil 1 isn't the best, it's at least close enough that it's still a safe bet. Just my .02