Why do you need 5W-50 if 10W-40 exists?

[HangerHarley]

5W-50 seems a weird, somewhat mystical product. Particularly when compared to 10W-40, or 5W-40. (Audi Junkie in particular made the case for 10W-40 on dparm's Audi S4. I dont have an Audi but the underlying principles are what concerns me, not the car.)

People say 5W-50 is still kind of thick-ish even though it is a "5W" (Id be satisfied it is a 5W) and then of course is a "Thin 50" at operating temp, more like a 40.

Im referring specifically to Castrol Syntec. It seems like a weird product, but certain cars really like it. Maybe even more than a 10W-40, maybe not. Im thinking it ends up more like their 5W-40?

Thoughts? Insight? Im asking any real benefits to a 5W-50 grade over 10W-40.

Let us assume we have an engine that "needs it" this really helps me get a feel for what oil does and does not do. 5W-50 still gives high-ish Oil Pressure.. ill have to test with Syntec 5W-40, and then GC.

I also dont have my car, ANY car, in front of me, so this is more to research beforehand, and walk in to a store and -confidently- buy something. Been leaning towards GC; re-researching Thicker stuff to balance that out.

Have at it!

 

[lexus114]

i dont think i`ll be using it any time soon. (although it`s listed as a factory fill/service for my vehicle on the new mb-1 website.)

 

[djquik1]

The Ford GT and Shelby GT500 are spec'd for the 5w50

 

[kcfx4]

This is interesting!!

 

[PandaBear]

Because the engine designer screwed up, so we need 5w50 to fix the worst case scenario.

 

[HangerHarley]

Originally Posted By: djquik1
The Ford GT and Shelby GT500 are spec'd for the 5w50


Believe me id like to buy that car (the Ford GT) just so i can say "hey look at me I have a car that im SUPPOSED to put Castrol Syntec 5W-50 in it" - and i would.

 

[Falcon_LS]

Interestingly enough, if you want to go with a full synthetic, the Ford dealer's only product is Motorcraft 5W-50 Full Synthetic. The GT was never officially sold here, at least to the best of my knowledge.

 

[kcfx4]

Think of the other side of the coin hangerharley, why was 10w40 made? things were so much simpler back then, prehaphs if they had the technology to have 5w50 then, we'd be asking the reverse of this question? seems a bit similar to the thick vs thin post? not trying to start a debate, just saying......

 

[Quattro Pete]

Originally Posted By: HangerHarley


Thoughts? Insight? Im asking any real benefits to a 5W-50 grade over 10W-40.

One thing I can think of is fuel dilution. On high powered engines, when fuel dilutes the oil, it'll turn from Xw-50 to Xw-40, and Xw-40 possibly still provides enough protection. If you started with Xw-40 and then fuel turned it into Xw-30, then under hard driving/high revving/high temp conditions, it may not longer offer enough wear protection.

Kind of like the use of 10w-60 in some of the BMW M engines.

 

[addyguy]

Castrol has ALWAYS been about large-spread, thick oils. It's sorta their 'specialty':

- Castrol was one of the first companies to develop a 20W-50 multigrade oil for the BMC mini engine/gearbox requirements;

- Castrol was one of the first (along with Shell) to develop a 10W-50 multi-grade oil in the early 1970's;

- Castrol was one of the first, if not THE first company, to develop a 10W-60 grade oil to help BMW with their engine problems;

- 'GC' was originally developed from Castrols 15W-50 grade racing oil;

- I might be wrong on this, but Castrol Edge 0W-40 has been out for a long time - it may have been one of the first 0W-40's developed. And, they do really well in Australia, where 0W-40, 20W-50, and 10W-60 oils do well.

- When 'Castrol Syntec' FIRST came out in the early 1990's, it was ONLY available in 5W-50, and it stayed that way for a good few years. Syntec 5W-50 is their oldest NA viscosity, and still a pretty popular one, I'd imagine.

A 5W-50 oil, in general, makes far more 'sense' than a 10W-40 - you gain a lot of cold-crank/flow ability over a 10W-40.

 

[d00df00d]

Originally Posted By: HangerHarley
5W-50 seems a weird, somewhat mystical product. Particularly when compared to 10W-40, or 5W-40. (Audi Junkie in particular made the case for 10W-40 on dparm's Audi S4. I dont have an Audi but the underlying principles are what concerns me, not the car.)

People say 5W-50 is still kind of thick-ish even though it is a "5W" (Id be satisfied it is a 5W) and then of course is a "Thin 50" at operating temp, more like a 40.

Im referring specifically to Castrol Syntec. It seems like a weird product, but certain cars really like it. Maybe even more than a 10W-40, maybe not. Im thinking it ends up more like their 5W-40?

Thoughts? Insight? Im asking any real benefits to a 5W-50 grade over 10W-40.

Let us assume we have an engine that "needs it" this really helps me get a feel for what oil does and does not do. 5W-50 still gives high-ish Oil Pressure.. ill have to test with Syntec 5W-40, and then GC.

I also dont have my car, ANY car, in front of me, so this is more to research beforehand, and walk in to a store and -confidently- buy something. Been leaning towards GC; re-researching Thicker stuff to balance that out.

Have at it!

If a car runs hot enough to need an SAE 50, but also needs to be able to run in very cold environments, 5w-50 is a great choice.

People have already mentioned certain hot Mustangs that spec 5w-50. Another such car is the McLaren-Mercedes SLR. It's designed to do cold starts all day long in the Arctic Circle in January (literally) and then run hot laps in Arizona in July, with no preparation or modification in between, and silky smooth operation at all times.

 

[Spazdog]

I used Bel-Ray Synthetique 15W50 motorcycle oil in my Kawasaki for the first 40,000 miles and Castrol GTX 20W50 for the next 40K. IIRC, the manufacturer specified 10W40.

I was young and didn't know any better. Always 3K OCIs. Used "affordable" Denis Kirk or Tucker Rocky filters (probably Chinese)

Like most Japanese motorcycles, the engine and transmission shared a common lubricant. By 80,000 miles 2nd gear was completely gone, 3rd had to be held in place with your toe and it would randomly "pop out" of 6th at freeway speeds. The transmission for all intents and purposes was gone. But the engine had good compression across all 4 cylinders and only Class 1 leaks at the valve cover and output shaft. I'm fairly certain that the XW50 had no negative effect. I just used that poor Kawi up by not owning a car for many years. The engine was still strong, it just couldn't apply that power to the rear wheel effectively.

 

[d00df00d]

Originally Posted By: addyguy
- Castrol was one of the first, if not THE first company, to develop a 10W-60 grade oil to help BMW with their engine problems;

That oil had been in development for decades by that time. A version of it was tweaked for BMW M engines, and it was introduced at the same time as when they fixed a manufacturing defect in one of their engines. It continues to be used for the new engines they have made since then. It's also used in race cars, as its predecessors have been since the beginning.

Not sure if it was the first 10w-60 oil, either.

It's probably the most popular one, though, and it's definitely the most proven.

 

[Hemi426]

My gasoline powered emergency generator calls for synthetic 5w-50. Usually Castrol Syntec 5w-50 is the only oil I can find. I'll have to keep my eyes open for other brands.

 

[Scienceman]

There is a thread that talks about a snowblower that calls for it.

 

[simple_gifts]

Quote:

My gasoline powered emergency generator calls for synthetic 5w-50. Usually Castrol Syntec 5w-50 is the only oil I can find. I'll have to keep my eyes open for other brands.


Redline makes a 5w-50

 

[Doug Hillary]

Hi,
addyguy - Just to clear up a few issues:

You said:
" Castrol was one of the first, if not THE first company, to develop a 10W-60 grade oil to help BMW with their engine problems;"

Not so - it was developed from Formula R 15W-50 that was introduced around 1976. BMW were not in that "mix" until later - Sauber-Mercedes used it in 1989 & 1990 to win the WSCC and LeMans in 1989. Porsche & BMW used this lubricant in this time. The deal was done with BMW sometime around 1999 when BP were sniffing around Castrol!

You said this:
" 'GC' was originally developed from Castrols 15W-50 grade racing oil;"

This is incorrect - Castrol Formula SLX 0W-30 (the original GC GC) was developed as a new breed of low (controlled) phosphorous, low cholorine oil in the early 1990s. It was castor based like Formula R was in the 1970s but it was a very different animal!

Castrol's 5W-50 lost Porsche Approval in 1999 - it was on that List as Syntec 5W-50, Super Racing and Syntron Extra. TWS Motorsport 10W-60 was also on the 1999 but lost Approval thereafter. The only 5W-50 lubricant on Porsche's Approved List after 1999 was and still is M1 5W-50

I could go a little further. Syntec was not introduced into OZ until the early/mid 2000s. This would have been a BP Marketing move I expect

And you are correct a 5W-50 viscosity makes very good sennse in some applications - just ask AMG!

addyguy - I hope this helps and I hope you are not offended by my Post

 

[hardcore302]

Originally Posted By: djquik1
The Ford GT and Shelby GT500 are spec'd for the 5w50


They love the 50 syntec

 

[porkchop01]

Originally Posted By: HangerHarley
5W-50 seems a weird, somewhat mystical product. Particularly when compared to 10W-40, or 5W-40. (Audi Junkie in particular made the case for 10W-40 on dparm's Audi S4. I dont have an Audi but the underlying principles are what concerns me, not the car.)

People say 5W-50 is still kind of thick-ish even though it is a "5W" (Id be satisfied it is a 5W) and then of course is a "Thin 50" at operating temp, more like a 40.

Im referring specifically to Castrol Syntec. It seems like a weird product, but certain cars really like it. Maybe even more than a 10W-40, maybe not. Im thinking it ends up more like their 5W-40?

Thoughts? Insight? Im asking any real benefits to a 5W-50 grade over 10W-40.

Let us assume we have an engine that "needs it" this really helps me get a feel for what oil does and does not do. 5W-50 still gives high-ish Oil Pressure.. ill have to test with Syntec 5W-40, and then GC.

I also dont have my car, ANY car, in front of me, so this is more to research beforehand, and walk in to a store and -confidently- buy something. Been leaning towards GC; re-researching Thicker stuff to balance that out.

Have at it!
How many threads can you start in one day?

 

[d00df00d]

Originally Posted By: porkchop01
How many threads can you start in one day?

Interested to know how you felt this would be a valuable contribution.