XD3 0w40 ok for 3.1 and 3.4 GM engine?

[CATERHAM]

BlazerLT

Your assumption that ESSO has no plans of coming out with a lighter XD-3 grade such as a 0W20 is correct. As you mentioned, it is intended for the Diesel market, so the demand isn't their for a lighter oil. The tech' person at Imperial Oil I spoke to was quick to suggest M1 for Gasoline Auto applications which defeats the whole price advantage of XD-3. I also asked, for fun, whether is was OK to blend XD-3 0W30 with some of M1's lighter oils like 0W20 to concoct a lighter 30wt oil and was advised no problem and their would be no additive clash, not that I thought their would be.

 

[BlazerLT]

The difference in viscosities will not net any differences in fuel economy that will validate twice the price.

XD3 0w30: 12.1
Mobil1 0w30: 10.3

Net difference: 1.8

-------------------------------------------------

Cost for oil (5L)

Esso XD3 0w30: CDN$20

Mobil1 0w30: CDN$38

Net difference: CDN$18

Amount of gas that extra CDN$18 can buy is: 19.80L or 5.25gal based on 0.90c/liter.

The difference in price of the oil change will far surpass and fuel economy losses with a cst difference of 1.8cst.

 

[CATERHAM]

At 100C the difference in viscosity between the two oils is significant; about half a grade or half the difference between XD-3 0W30 & 0W40 or the full difference between Mobil 1 0W30 and 0W20 -a full grade! But more importantly, since Mobil 1 has a higher VI than XD-3 the difference between the two formulations becomes more pronounced as the temperature drops. For example, at -20C the kinematic viscosity of XD-3 is 2962 cSt while Mobil 1 is only 1995 cSt. So when you factor in the fact that in the winter here in Ontario most cars will spend most of the time with oil temps below 100C I think the fuel savings would be measureable. Using your 5 gallon example and say a 10000 mile OCI the break even point would be 1/2 mpg based on a nominal 30mpg. Is that acheiveable? I think so; depending on the application it could be 2 or 3 mpg - who knows.
One way to possibly find out since we are just talking viscosity here, is to ask Imperial oil and/or Exxon/Mobil. Since it is the same company we should be able to get a straight answer.
Or simple ask Mobil if there are any stats' between their own oils and extrapolate from there.
As a reminder, if it were summer I'd be the first to admit the difference would not be worth fussing about and clearly XD-3 is an excellent value choice.

 

[BlazerLT]

But you do understand that the operating temperature for an engine is 100c right?

1.8cst at 100c is not a significant difference at all.

[ December 12, 2005, 11:53 PM: Message edited by: BlazerLT ]

 

[BlazerLT]

At -25c this is the difference in viscosities:

Esso XD-3 0w30: 4806
Mobil1 0w30: 3174
Mobil1 5w30: 4209
Castrol GTX 5w30: 4660 (-30 is its lowest pour point)

I doo see the relative difference at -25c here but they are both still easily pumpable at that temperature.

Mobil1 has always been known to be an extremely thin 30 weight when compared to most oils on the market.

I included the GTX to show you what I would be using if I wasn't using a synthetic.

 

[CATERHAM]

No, the operating oil temp' of all engines is not 100C; some are higher (turbo engines) some are lower. 85-90C is not uncommon. The Ferrari Maranello I mentioned earlier in this thread is 85-90C in normal street usage. But thats' missing the point, even if the operating temp' is 100C, in the winter it is frequently not achieved. My 15 km commute to work is, more often than not, insufficient to get the oil temperature up high enough and long enough to prevent condensation from building up in the engine. My point is that in the winter, for many if not most of us, our engines are running at less than the optimum temperature with a much higher kinematic viscosity than the optimum 10-13C cSt. That may not be good but it is reality. If it were physically possible this ideal viscosity would be maintained independant of temperature but unfortunately it is impossible. The next best thing is to have absolutely the lowest viscosity possible above the ideal viscosity until the 10-13C cSt is acheived. This is an important concept to grasp to begin to understand lubrication. Before an engine gets up to operating temp' even 0W20 is too thick.
You may want to check out some of Dr. A.E. Haas'
threads elsewhere in this forum where this is explained in much more detail.

 

[BlazerLT]

This is true and I am not arguing with you.

I am just saying that the relative difference in viscosity is not something I am concerned with when using this oil in colder temperatures.

A slightly thicker oil will also have the tendency to have a little more surface tension when cooling and will actually coat surfaces within the engine whereas thinner oil will tend to not coat as much and therefore it will be relying more on pump lubrication rather than residual left from the last time the engine was run.

This has a limit though and you don't want to go too thick.

For my application on an older engine, a little thicker oil will do it some good and keep oil consumption lower seeing the slightly thicker oil will not be blowing by the rings quite as easily.

 

[CATERHAM]

This is the advantage of a Polar element, such as MoS2 (Moly) and/or Esters depending on temperature that actually bonds to metal. In the case of Esters this occurs at the molecular level. Straight PAO's are inert like conventional oil and don't perform this function. They will run off metal in short order regardless of viscosity.
And on that note I'm off to bed.

 

[BlazerLT]

There is no such thing as a straight PAO based oil anymore.

Although the majority is PAO, there is always a portion od synthetic ester complex added to neutralize any shrinking effect PAO oils shave on seals. Esters tend to swell seals and PAOs tend to shrink hence why they always use a misture of the two.

 

[Fumes]

Where do you find the oil for $20. I was quoted $5.21 a liter for 0W40 in Regina at a distributor.