Is high HTHS still important for a normal vehicle?

Status
Not open for further replies.
But would you think there would still be the same level of engine protection if you ran a 0W-20 with a HTHS of 2.5 cP in that engine? That's what I'm asking. Why do you think your OM calls out oils with 3.5 HTSH or more? Could it be that the engineers know it's going to give more engine protection (and care less about CAFE) than an oil with HTHS of 2.5 cP? I'd say the answer is yes.
I didn't know this was even up for discussion. Why would I stick to the carmaker's minimum HTHS requirement if I thought I could reap the benefits of lower viscosity without wear and service life penalty? If the car maker suggests a different HTHS for different markets my choice is clear to me.
 
Last edited:
I didn't know this was even up for discussion. Why would I stick to the carmaker's minimum HTHS requirement if I thought I could reap the benefits of lower viscosity without wear and service life penalty? If the car maker suggests a different HTHS for different markets my choice is clear to me.
I highly doubt there is anything special about that Mini engine that would require a HTHS of 3.5 or higher. More likely the engineers specified that oil not caring about CAFE and more about engine wear protection and longevity. Maybe they think owners are going to track the car some too. I'm sure that engine could do just fine on a lower HTHS, but the overall wear may be a bit higher down the road. This is the balance that USA car makers are doing under the gun of CAFE. Sure you don't want to try some xW-20 or xW-16 in it, lol.

Why do you think it was specified to use the oil it does? It wasn't a dart board decision.
 
Last edited:
I highly doubt there is anything special about that Mini engine that would require a HTHS of 3.5 or higher. More likely the engineers specified that oil not caring about CAFE and more about engine wear protection and longevity. Maybe they think owners are going to track the car some too. I'm sure that engine could do just fine on a lower HTHS, but the overall wear may be a bit higher down the road. This is the balance that USA car makers are doing under the gun of CAFE. Sure you don't want to try some xW-20 or xW-16 in it, lol.

Why do you think it was specified to use the oil it does? It wasn't a dart board decision.
You are implying so many things that I did not say that it's comical. And why do you think I disagree with you? How exactly did I set you off? Slow day? As for CAFE, I have never followed oil recommendations based on CAFE considerations and I don't intend to ever do so.
 
Last edited:
You are implying so many things that I did not say that it's comical. And why do you think I disagree with you? How exactly did I set you off? Slow day? As for CAFE, I have never followed oil recommendations based on CAFE considerations and I don't intend to ever do so.
LoL, nothing "set me off", I'm just asking some simple questions which you seem to not have any answer for, which seems "comical".Your owner's manual already specs an oil with pretty high HTHS, but what if it didn't? Would you run a CAFE driven xW-20 if the OM only gave that oprion, or would you think outside the OM box and use something with more viscosity/HTHS based on Tribology and technical discussions on this site?
 
Manuals (in the USA at least) are specifying oil based on an absolute minimum to meet CAFE while at the same time not make the engine fail. But that doesn't mean that the CAFE driven low oil viscosity called out in the OM is giving the best protection from wear. There is a trade off between increased fuel mileage and increased wear as the oil gets thinner and thinner.
Which is why our CR-V'S with the 1.5t engines, which reccomend an API 0W-20 are now spinning quite happily using Mobil 1 Extended Performance 5w30 and according to my Honda Certified Master Technician, will do so longer than with 0W-20.
 
LoL, nothing "set me off",
Yet you keep poking.
I'm just asking some simple questions which you seem to not have any answer for
I gave you too much credit when I thought you could parse what I said.
, which seems "comical".
I'm glad you are amused.
Your owner's manual already specs an oil with pretty high HTHS, but what if it didn't?
I would not buy a vehicle with an engine that specs low HTHS oil to begin with. If the manuals for different markets differ in the recommendation I will not go with the lower HTHS recommendation.
Would you run a CAFE driven xW-20 if the OM only gave that oprion, or would you think outside the OM box and use something with more viscosity/HTHS based on Tribology and technical discussions on this site?
I would not run anything below XW-30 unless the relentless questioning didn't stop after 48 hours.
 
Yet you keep poking.

I gave you too much credit when I thought you could parse what I said.

I'm glad you are amused.
Who's actually "set off" based on those replies, lol.

I would not buy a vehicle with an engine that specs low HTHS oil to begin with. If the manuals for different markets differ in the recommendation I will not go with the lower HTHS recommendation.
It's not against the law (yet) to put thicker oil in engines speced for thin oils. Opens up a larger vehicle purchasing pool to choose from. Car buyer looking at vehicles: "I really love this car, it checks all the boxes - but what viscosity oil does it call out in the OM"? Sales guy: "Only 0W-16". Buyer: "What else you got on the lot"? 😄;)

I would not run anything below XW-30 unless the relentless questioning didn't stop after 48 hours.
I'm gonna keep asking questions until you put some 0W-20, or even some 0W-5 racing oil (after a week of questions) in that Mini. 😄
 
It's a compromise, for example in manual Toyota specifies different viscosities, so and HTHS are.
But the big issue is the design of the engine, some one of them can easily reach 200 k, some are more troublesome. My comment is for 15-20 years old cars.
For example my corolla was driven in Spain 8 years with 15w40 with no issues.
In my hands the corolla was driven with 5w30 C3, 5w40 and 0w40, easy on oil.
 
Which is why our CR-V'S with the 1.5t engines, which reccomend an API 0W-20 are now spinning quite happily using Mobil 1 Extended Performance 5w30 and according to my Honda Certified Master Technician, will do so longer than with 0W-20.
What data is this guy basing that on?
 
What data is this guy basing that on?
Probably due to the number of Civics, Accords and CRVs equipped with the 1.5t engines. who's owners follow Hondas MM and run 0w20 for 6-8000 miles the oil is way above the full mark on the dipstick when brought in for service (very few people ever check oil any more)......or tire pressure, but I digress, and the oil is like water and reeks of gasoline when drained. We've discussed this several times, indicated I should use a xx-30 oil and change between 3-4000 miles. Trying this now and noting very little rise on the stick, engine is noticeably quieter, no loss of power and perhaps a 1-2 loss of mpg (yes, I actually calculate this). Interesting, have noticed that when the ambient temperature is 55 or higher, my highway mpg goes back up into its normal 33-35 mpg range. Dealer indicates that using a API GF-6 5w30 instead of 0w20 won't effect my warranty as long as OCI'S are reasonable, some, not all, Honda 1.5t"s are hard on oil, depending on use, so, somewhat shorter OCI'S seem to be the solution for me keeping a car I like for a longer period without oil-related problems.
 
Probably due to the number of Civics, Accords and CRVs equipped with the 1.5t engines. who's owners follow Hondas MM and run 0w20 for 6-8000 miles the oil is way above the full mark on the dipstick when brought in for service (very few people ever check oil any more)......or tire pressure, but I digress, and the oil is like water and reeks of gasoline when drained. We've discussed this several times, indicated I should use a xx-30 oil and change between 3-4000 miles. Trying this now and noting very little rise on the stick, engine is noticeably quieter, no loss of power and perhaps a 1-2 loss of mpg (yes, I actually calculate this). Interesting, have noticed that when the ambient temperature is 55 or higher, my highway mpg goes back up into its normal 33-35 mpg range. Dealer indicates that using a API GF-6 5w30 instead of 0w20 won't effect my warranty as long as OCI'S are reasonable, some, not all, Honda 1.5t"s are hard on oil, depending on use, so, somewhat shorter OCI'S seem to be the solution for me keeping a car I like for a longer period without oil-related problems.
Your CVT is going to die way before oil makes a difference in that engine. Techs are not a reliable source of information generally. I’m not saying I disagree, but still.
 
In my opinion, CAFE inspired owner's manual oil viscosity and oil change intervals are not good for your engine's longevity.
I prefer to use a HTHS >= 3.2 5w30 and do an oil change interval of 4k miles
(Even though my vehicles are speced for 20 weight oils, and Honda Maintanance minder usually hits 15% at around 5500 miles).

My son recently got a speeding ticket for going 90 MPH (which he was doing for a sustained period of time on the highway).
I had a talk with him about the safety implications about driving that fast.
But a secondary less important consideration was engine wear. Luckily I had the 5w30 HTHS >= 3.2 in the engine, so it had sufficient
MOFT to prevent any engine wear.

I know many users on this board always say: trust your owners manual. The engineers who built you car know best.
But with owner's manuals specing 0W-16 and even 0W-8 with 10k oil change intervals, how can anyone follow their owners manual anymore?

Just google HTHS wear graph.
See for yourself how exponential wear occurs once HTHS drops below 2.6.
 
Last edited:
Your CVT is going to die way before oil makes a difference in that engine. Techs are not a reliable source of information generally. I’m not saying I disagree, but still.
This. My son is a tech....he is not a SME on oil nor the impacts of varying it on engine longevity.
 
Your CVT is going to die way before oil makes a difference in that engine. Techs are not a reliable source of information generally. I’m not saying I disagree, but still.
When it's obvious to all that the "follow your owners manual viscosity recommendation" logic is flawed, the thin crowd's last line of defense is the car will rust out or have some other more pressing failure before the engine dies from wear. LOL.

Why fight giving your engine more protection. Instead embrace oils with higher HTHS/MOFT.
 
Your CVT is going to die way before oil makes a difference in that engine. Techs are not a reliable source of information generally. I’m not saying I disagree, but still.
Techs rebuild engines, and have had special training on how cars work. They are the most credible authority on OCI and viscosities.
Most Techs I've ever spoken to say change oil every 3k to 5k miles and use 5w30. I believe they are right.
 
Status
Not open for further replies.
Back
Top Bottom