Just have a few Q's on synthetics

[Nicasio]

-So since Euro cars have a different (higher??) standard. Would I benefit from running a Euro spec oil vs. our domestic oil in my vehicles?

-Since most engine wear occurs during cold start ups. Wouldn't 0w- oil be better than any 5w- or 10w- oil?

-Are all 5w-40 heavy duty oils bad for catalytic converters?

I try to buy everything from Walmart or Amazon.

 

[09_GXP]

Originally Posted By: Nicasio
-So since Euro cars have a different (higher??) standard. Would I benefit from running a Euro spec oil vs. our domestic oil in my vehicles?


That depends on what you define as "benefit." You will likely see less wear but also less fuel economy with a Euro spec oil. Whether you could measure either effect is questionable.

Originally Posted By: Nicasio
-Since most engine wear occurs during cold start ups. Wouldn't 0w- oil be better than any 5w- or 10w- oil?


For most production engines, yes. Again, would be tough to quantify.

Originally Posted By: Nicasio
-Are all 5w-40 heavy duty oils bad for catalytic converters?


The oil will have higher levels of additives that are bad for catalytic converters. If the vehicle burns oil it is a bigger concern. You cat will die sooner but I have not seen enough research to say how much sooner.

 

[69GTX]

Oils are only bad for catalytic converters if the oil blows by and ends up in the exhaust. No problem if you don't have any usage.

The most engine wear occurs from turning the key all the way up until a 175 deg oil temp is reached. Most of that wear occurs when the oil is at pressure and warming up. During the initial start, the thicker oil will protect better than the 0w as only leftover film strength is protecting your engine. Hence in warmer climates you might see 10w and 15w oils used a lot. At -40c startups, the 0w is a big plus. At -30c they both are adequate. The 0w oils are used a lot because the 0w30 and 0w-40 oils offer a package that regular 5w30's don't typically have.

 

[Quattro Pete]

Originally Posted By: Nicasio
-Are all 5w-40 heavy duty oils bad for catalytic converters?

No. There are plenty of mid/low SAPS HD oils out there that are no worse for your cat converter than any other API SN oil.

 

[ChrisD46]

Which would have the lesser VI's : 0W20 / 0W30 or 5W20 / 5W30 ? That may be an aditional question to ponder than just the 0W question ...

 

[E150GT]

Originally Posted By: 69GTX
. The 0w oils are used a lot because the 0w30 and 0w-40 oils offer a package that regular 5w30's don't typically have.

What package would that be?

 

[CourierDriver]

I have some friends that run freight in Sprinters, Mercedes engines, and from their experience ,they only run European oil specs , no American brands, whatever the Mercedes manual calls for,,they run that type only. so, beware, check with the dealership,,,you don't wont to ruin your engine..

 

[SR5]

Originally Posted By: E150GT
Originally Posted By: 69GTX
. The 0w oils are used a lot because the 0w30 and 0w-40 oils offer a package that regular 5w30's don't typically have.

What package would that be?

I'm not 69GTX, but I think he is saying that many 0W30/40 oils are Euro ACEA A3/B4 rated while many 5W30 oils are SN & GF-5 rated. I'm sure there are exceptions, but the majority are probably that. In which case the Euro oils tend to have a different add pack with higher SAPS and TBN. Plus the Euro oils would have a higher HTHS (3.5 cP or more) which produces a thicker/stronger oil film.

 

[69GTX]

Originally Posted By: SR5
Originally Posted By: E150GT
Originally Posted By: 69GTX
. The 0w oils are used a lot because the 0w30 and 0w-40 oils offer a package that regular 5w30's don't typically have.

What package would that be?

I'm not 69GTX, but I think he is saying that many 0W30/40 oils are Euro ACEA A3/B4 rated while many 5W30 oils are SN & GF-5 rated. I'm sure there are exceptions, but the majority are probably that. In which case the Euro oils tend to have a different add pack with higher SAPS and TBN. Plus the Euro oils would have a higher HTHS (3.5 cP or more) which produces a thicker/stronger oil film.


Thanks SR5. Along with that A3/B4 spec usually comes higher levels of additives like Ca, Phos, and Zinc (ie "the package").

 

[CT8]

The wear from cold starts isn't necessarily oil related. If the temps are too cold for the oil to pump or pump properly well yes. But cold start wear is caused by condensation when the metals are cold, the richer air fuel mixture washing the oil from the cyls, the pistons not being round when cold[if you doubt me measure them]The clearances being more because the metals aren't expanded etc.

 

[Nicasio]

Thanks for all the replies folks. Really cleared some things up. I don't beat any of my cars. I'm for the most protection, performance, over gas mileage. Few more Q's for y'all:

-Would the heavy duty diesel synthetic be more protective vs. the same temp/weight gasoline car synthetic?
-Also, which is the best 5W-40 heavy duty/diesel synthetic available from Walmart that's least damaging to the catalytic converters. I think I remember seeing Rotella T6, Delo 400, Delvac1, & Turbo Diesel Truck?

 

[weasley]

Originally Posted By: CT8
The wear from cold starts isn't necessarily oil related. If the temps are too cold for the oil to pump or pump properly well yes. But cold start wear is caused by condensation when the metals are cold, the richer air fuel mixture washing the oil from the cyls, the pistons not being round when cold[if you doubt me measure them]The clearances being more because the metals aren't expanded etc.


That covers the pistons, but what about the rest of the engine? ZDDP doesn't really start working until it gets warm, so you are relying a lot on hydrodynamic protection during the warm-up phase. This dovetails nicely with the larger clearances you mention in the bores, but the camshafts still need protection from high loads.

The Sequence IVA test used in API SN and ILSAC GF-5 is a valve-train wear test and is run for 100 hours with the oil and coolant temperatures kept forcibly low - it essentially spends 100 hours in a warm-up mode.