importance of oil weight

JasonWatts · **Posted:** Mon Mar 11, 2013 11:28 am

so, when dealing with fully synthetic, I know the first number does not matter. but what of the 2nd? I am thinking of running that rotella stuff in some of my vehicle, but am slightly deterred by some of them not specifying a 40w oil.

JamesShort · **Posted:** Mon Mar 11, 2013 11:33 am

I just tried google translate from Mandarin and it's not that much more understandable. Checkout the oil thread or peruse BITOG.

Second number in a multigrade oil is the kinematic viscosity of the oil at 100degC. Most engines can operate quite well over a pretty broad range of operating temp viscosities and MFGs spec the lightest oil they can so that fuel economy numbers are 1-2% better for their EPA sticker numbers.

Which cars, the miata?

Steven Carter · **Posted:** Mon Mar 11, 2013 11:40 am

JamesShort wrote:

The answer is German Castrol

Fixored.

JasonWatts · **Posted:** Mon Mar 11, 2013 11:47 am

JamesShort wrote:

I just tried google translate from Mandarin and it's not that much more understandable. Checkout the oil thread or peruse BITOG.

Second number in a multigrade oil is the kinematic viscosity of the oil at 100degC. Most engines can operate quite well over a pretty broad range of operating temp viscosities and MFGs spec the lightest oil they can so that fuel economy numbers are 1-2% better for their EPA sticker numbers.

Which cars, the miata?

lesabre and the silverado for now. I know the lesabre requires 30w and I believe the truck does as well. so going with a 40w should be perfectly fine then?

JamesShort · **Posted:** Mon Mar 11, 2013 11:51 am

Steven Carter wrote:

JamesShort wrote:

The answer is German Castrol

Fixored.

Or M1 0w40 (it pains me to suggest M1, but ONLY that weight).

Richard Casto · **Posted:** Mon Mar 11, 2013 1:15 pm

I defer to James regarding oil info (I may post later to get recommendations on what to use for the Fit), but I am going to be pedantic about one thing. It is a button for me. And that is the term "weight" to describe oil. As far as I can tell, it is not a valid term for oil. The "W" (such as in 0W-30) is not "Weight", but "Winter". It is to indicated the cold temperature viscosity. So "0" when cold, "30" when hot.

Richard

JamesShort · **Posted:** Mon Mar 11, 2013 1:49 pm

Richard Casto wrote:

I defer to James regarding oil info (I may post later to get recommendations on what to use for the Fit), but I am going to be pedantic about one thing. It is a button for me. And that is the term "weight" to describe oil. As far as I can tell, it is not a valid term for oil. The "W" (such as in 0W-30) is not "Weight", but "Winter". It is to indicated the cold temperature viscosity. So "0" when cold, "30" when hot.

Richard

Yes, 0W, 5W, 10W, 20, 30, 40 are all 'weights'. The W does not stand for weight as both the 'XW' and 'Y' in a XWY are weights (kinematic viscosity **ranges** at 40degC and 100dedC respectively).

Richard Casto · **Posted:** Mon Mar 11, 2013 2:04 pm

JamesShort wrote:

Richard Casto wrote:

I defer to James regarding oil info (I may post later to get recommendations on what to use for the Fit), but I am going to be pedantic about one thing. It is a button for me. And that is the term "weight" to describe oil. As far as I can tell, it is not a valid term for oil. The "W" (such as in 0W-30) is not "Weight", but "Winter". It is to indicated the cold temperature viscosity. So "0" when cold, "30" when hot.

Richard

Yes, 0W, 5W, 10W, 20, 30, 40 are all 'weights'. The W does not stand for weight as both the 'XW' and 'Y' in a XWY are weights (kinematic viscosity **ranges** at 40degC and 100dedC respectively).

I think we are mostly saying the same thing. My opinion is that the term "weight" has taken on a life of it's own, when in fact (as you say) it is really viscosity (kinematic viscosity). See if you can find any documentation anywhere that defines "oil weight" other than loosely using "Weight" and "Viscosity" interchangeably. I think "grade" or "viscosity grade" is more accurate than "weight". Anyhow, my main beef is that I think a lot of people think that the "W" in "0W-30" or "30W" means "Weight" when it doesn't.

Richard

JamesShort · **Posted:** Mon Mar 11, 2013 2:12 pm

All layman's terminology for describing motor oil in general are terrible. Lots of them are ranges that are loosely defined. Lots of misinformation about almost everything so I agree that the weight thing is one of these (of many).

The L15 is proving to be quite a robust beast (d series style). I'd bet you could run Walmart Supertech 5w20 conventional for 500k+ miles without issues.

That being said, I'm also an Amsoil fan. But for a non performance engine that isn't known for burning oil or being 'hard' on oil, I'd probably say an off the shelf Group 3+ synthetic would be more than appropriate for 10k oil change intervals. Every 0w20 oil is already at least Group 3/3+ synthetic. I've been running the Accords K24 (specs 5w20) on Penzoil Platinum 5w20 (always get in on sale for less than $30 for 5+ qts) for 10k OCIs since it had 0 miles. It doesn't burn anything and isn't noisy and the cam lobes are mirror like in finish.

Richard Casto · **Posted:** Mon Mar 11, 2013 2:19 pm

JamesShort wrote:

The L15 is proving to be quite a robust beast (d series style). I'd bet you could run Walmart Supertech 5w20 conventional for 500k+ miles without issues.

Thanks for the tips regarding the Honda Fit (L series engine). I have read up on it, and it seem like Honda wants the best qualities of the D series when they designed the L series, but in a smaller, more efficient package. Knock on wood it will prove to be as good to me as my two D series engines have.

Richard

JamesShort · **Posted:** Mon Mar 11, 2013 2:21 pm

Richard Casto wrote:

JamesShort wrote:

The L15 is proving to be quite a robust beast (d series style). I'd bet you could run Walmart Supertech 5w20 conventional for 500k+ miles without issues.

Thanks for the tips regarding the Honda Fit (L series engine). I have read up on it, and it seem like Honda wants the best qualities of the D series when they designed the L series, but in a smaller, more efficient package. Knock on wood it will prove to be as good to me as my two D series engines have.

Richard

I should qualify that I meant 500k+ miles with reasonable OCIs 7500-10k miles

....not 500k miles straight

.

Richard Casto · **Posted:** Mon Mar 11, 2013 2:31 pm

JamesShort wrote:

Richard Casto wrote:

JamesShort wrote:

The L15 is proving to be quite a robust beast (d series style). I'd bet you could run Walmart Supertech 5w20 conventional for 500k+ miles without issues.

Thanks for the tips regarding the Honda Fit (L series engine). I have read up on it, and it seem like Honda wants the best qualities of the D series when they designed the L series, but in a smaller, more efficient package. Knock on wood it will prove to be as good to me as my two D series engines have.

Richard

I should qualify that I meant 500k+ miles with reasonable OCIs 7500-10k miles

....not 500k miles straight

.

Crap, you mean I gotta change it!

I haven't read deeply enough, but there seems to be lots of talk as to oil change interval on the Fit. It has an oil life indicator (that I think it purely mileage based). And I think it probably assumes synthetic with extended service intervals.

Richard

JamesShort · **Posted:** Mon Mar 11, 2013 2:43 pm

Richard Casto wrote:

Crap, you mean I gotta change it!

I haven't read deeply enough, but there seems to be lots of talk as to oil change interval on the Fit. It has an oil life indicator (that I think it purely mileage based). And I think it probably assumes synthetic with extended service intervals.

Richard

If you follow the MM, you will likely be heading towards 15k mile OCIs. My Accord's MM probably would get me to 12-13k miles if I waiting till it was at <15%. I do 10k OCIs so I can remember easy and the MM is usually at 35-40%.

Stephen Westerfield · **Posted:** Mon Mar 11, 2013 5:46 pm

Our 2007 Fit is the first car I've had that I said I would just follow what the maintenance minder said and go by the book. The light has come on pretty consistently between 5750 and 6000 miles every time. It's about to roll over 100k miles at just under 6 years. I've used Castrol GTX 5W-20 and had zero issues with the car. I wouldn't try to over complicate things.

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Richard Casto wrote:

I have read up on it, and it seem like Honda wants the best qualities of the D series when they designed the L series, but in a smaller, more efficient package.

Best qualities ?!?! As in the D series propensity to spin rod bearings and blow head gaskets? No thanks!

Haha, those were from our days before we figured out the secret formula about how to bolt together (endurance racing) reliable honda engines

Sorry for the digression

Mike (B series snob at the moment)

THSCC Forums

importance of oil weight

Who is online