Redline 0w40, 5w40 and 10w40: What is the difference?

The vehicle will only be driven in warm weather, so even 25W would not be an issue.

Yes that is what I am trying to understand regarding 5w and 10w oils they have. Eactly the same pour point, 40C KV, and HTHS. 5w has a higher VI and a bit higher 100C KV. I am not sure howcome one is 5W and the other is 10W. I guess the only difference is the amount of VII.
Write or call Redline, tell them your application and ambient cold start temp. and they will advise you.
Otherwise, I would choose 0W-40 even if it's for summer use only.
 
The vehicle will only be driven in warm weather, so even 25W would not be an issue.

Yes that is what I am trying to understand regarding 5w and 10w oils they have. Eactly the same pour point, 40C KV, and HTHS. 5w has a higher VI and a bit higher 100C KV. I am not sure howcome one is 5W and the other is 10W. I guess the only difference is the amount of VII.
Warm only = 10w40 and no worries.
 
To the OP, I've noticed some interesting findings in their SDSs and listed approvals (well, recommendations would be more accurate as they don't seek approvals) as well, and I've asked for some clarification in the past. They don't seem particularly keen to keep them up to date or pay much attention to keeping them accurate.

I would definitely go with 10W-40. Zero reason to go with their 0W-xx or 5W-xx options in your use case. Might as well enjoy the lower VII load.
 
To the OP, I've noticed some interesting findings in their SDSs and listed approvals (well, recommendations would be more accurate as they don't seek approvals) as well, and I've asked for some clarification in the past. They don't seem particularly keen to keep them up to date or pay much attention to keeping them accurate.

I would definitely go with 10W-40. Zero reason to go with their 0W-xx or 5W-xx options in your use case. Might as well enjoy the lower VII load.
Yes sir, that is precisely what I did.
Might be an overkill with such a high hths, but why not:)

Lake had a video where he compared bunch of oil and found redline by far had the highest temp, even beyond what it being the highest in that grade can explain. That is the only reservation I have but no doubt it it will provide good protection
 
Yes sir, that is precisely what I did.
Might be an overkill with such a high hths, but why not:)

Lake had a video where he compared bunch of oil and found redline by far had the highest temp, even beyond what it being the highest in that grade can explain. That is the only reservation I have but no doubt it it will provide good protection
Which car out of curiosity?

I've actually thought about running that 10W-40 too... HTHS at a level wear will be nonexistent and a Noack at 5-6%.

I agree Red Line doesn't have the best results in tests, but it does seem to perform really well in the real world. Can't remember anyone ever having a bad experience with it here.
 
Which car out of curiosity?

I've actually thought about running that 10W-40 too... HTHS at a level wear will be nonexistent and a Noack at 5-6%.

I agree Red Line doesn't have the best results in tests, but it does seem to perform really well in the real world. Can't remember anyone ever having a bad experience with it here.

I heard a couple classic car owners hating it as they believe it messed up with the gasgets and lead to oil leak. But I am pretty sure that was due to it cleaning what conventional oil left behind.

It is for a Ferrari 348
 
I heard a couple classic car owners hating it as they believe it messed up with the gasgets and lead to oil leak. But I am pretty sure that was due to it cleaning what conventional oil left behind.

It is for a Ferrari 348
Wow nice car.

Does the Red Line have the right additive pack for that engine? Looks like the modern equivalent for that would ACEA A3/B4 which those Red Line offerings should clear easily.
 
I heard a couple classic car owners hating it as they believe it messed up with the gasgets and lead to oil leak. But I am pretty sure that was due to it cleaning what conventional oil left behind.
In general, anyone complaining about oil leaks with a particular oil (Red Line, or other oil, but usually a synthetic)... the root cause is old, worn seals that needed to be replaced anyway.

I've never heard of an issue with RL or other synthetic leaking past NEW seals, where a conventional oil did not leak with the same new seal.

Disclaimer: I use Red Line 10W-40 in most of my Mercedes M119 V8 gas engines.

🤔
 
In general, anyone complaining about oil leaks with a particular oil (Red Line, or other oil, but usually a synthetic)... the root cause is old, worn seals that needed to be replaced anyway.

I've never heard of an issue with RL or other synthetic leaking past NEW seals, where a conventional oil did not leak with the same new seal.

Disclaimer: I use Red Line 10W-40 in most of my Mercedes M119 V8 gas engines.

🤔
You are definitely right. That leak does mean the seals were bad in the first place.
I think what happens is though, conventional oil leads considerable amount of deposit there, and when once switches to a synt oil, especially a very good one such as redline, that exposes the issues at seals by cleaning those deposits that prevents the leak. So what the end user sees is "Redline lead leaking" and interpret that more like "the PAO must have damaged the seals" or something in the lines of that.
But I agree with your opinion 100%. That does mean the seals needed a fix anyways. But its also true that one could get away with more years by not switching to these higher quality oil
 
Wow nice car.

Does the Red Line have the right additive pack for that engine? Looks like the modern equivalent for that would ACEA A3/B4 which those Red Line offerings should clear easily.
I do think so. Those engines are 35 years old. I would think pretty much any oil today must be considerably better than the Pennzoil of their time
 
I do think so. Those engines are 35 years old. I would think pretty much any oil today must be considerably better than the Pennzoil of their time
I said pennzoil because that is what is spelled by the manufacturer. Considering how small of their market is this brand, I think that is mostly due to sponsorship and marketing decision rather than targeted engineering


(Not meanong to spam, but I could not find how to edit this comment)
 
Why? That makes no sense.
In general 0W oils use better base stock oils to cover the 0W grade. For that reason in Mobil and Castrol oils the 0W-40 grade is always preferred over 5W-40.

And 10W-40 is even lower considering base stock oils that's why most of the companies din't bother to have it.

That's what I've learned from people on here.
 
Last edited:
Yeahbut... the reduced spread (0-40 vs 10-40) should also mean less VI's in the 10-40, so there's that. I'm not sure how much of a difference the "better" base stock makes, when comparing RL to RL.

🤓
 
Yeahbut... the reduced spread (0-40 vs 10-40) should also mean less VI's in the 10-40, so there's that. I'm not sure how much of a difference the "better" base stock makes, when comparing RL to RL. 🤓
Well, if high performance oils mostly come in 0W-40 grade and not 10W-40. That means something, right? It's not only the base oils.
In stock cars like Corvette, Porsches other German cars one of the most recommended oil (from the manufacturer) is 0W-40 oil, not 10W-40. Why is that?

Why the Porsche C40 GT cup oil is 0W-40 and not 10W-40?
https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/products/mobil-1-c40-gt-0w-40
 
Last edited:
"High performance" is a generic marketing term that is sorta meaningless IMO.

Most 0W-anything oils are aimed at fuel economy, not performance, longevity, or power production. (Excluding drag-race specific, ultra low viscosity oils that are meant to survive a single quarter-mile.)

😶
 
Back
Top Bottom