Why is Semi-Synthetic oil often recommended?
Discussion
Why is Semi-Synthetic oil often recommended for the speed six? (10w40 seems to be the general opinion)
The only real advantage to Semi over Fully-synth seems to be that it is cheaper. But not but a huge amount really.
The advantages to fully-synth surely outweigh that? Particularly for an engine that has lubrication flow issues when cold:
- It's better at withstanding hot and cold temps
- It flows better
- It produces less sludge / deposits
- It creates a more robust film at high temp / high load
Maybe I'm missing something?
Any oil gurus out there?
The only real advantage to Semi over Fully-synth seems to be that it is cheaper. But not but a huge amount really.
The advantages to fully-synth surely outweigh that? Particularly for an engine that has lubrication flow issues when cold:
- It's better at withstanding hot and cold temps
- It flows better
- It produces less sludge / deposits
- It creates a more robust film at high temp / high load
Maybe I'm missing something?
Any oil gurus out there?
Try Google. There are at least 15 pages of relevant results which will probably take you a few months to read, if you read them all.
Eventually, you will come across an article that says the global oil sales market is worth US$7,463.38 million. It will also tell you that there isn't even an accepted definition of synthetic.
Is semi 50/50? 80/20 what? Who knows what one brand does compared with another.
So, as usual, you might conclude that it's more about trying to part you with as much of your hard earned cash as possible.
And it all depends where you are in the world. The USA is obsessed with oil changes. There are seemingly as many drive in oil change places as drive in fast food. Some even have a clock that starts to count down as soon as you drive in, and if the oil change isn't done in 10 minutes or whatever it is, then you don't have to pay. There are TV adverts encouraging you to go for an oil change and which brand of oil to have. That doesn't exist in the UK. No one with a normal car would change the oil every 3000 miles. The fleet market would never accept it.
I suppose that it ensures that the oil level is always topped up (providing that you trust the garage)
Like most things in life, you just need to buy something reasonable of the right grade, unless once you have read all those Google search results you can tell us what the Holy Grail of oil is.
Eventually, you will come across an article that says the global oil sales market is worth US$7,463.38 million. It will also tell you that there isn't even an accepted definition of synthetic.
Is semi 50/50? 80/20 what? Who knows what one brand does compared with another.
So, as usual, you might conclude that it's more about trying to part you with as much of your hard earned cash as possible.
And it all depends where you are in the world. The USA is obsessed with oil changes. There are seemingly as many drive in oil change places as drive in fast food. Some even have a clock that starts to count down as soon as you drive in, and if the oil change isn't done in 10 minutes or whatever it is, then you don't have to pay. There are TV adverts encouraging you to go for an oil change and which brand of oil to have. That doesn't exist in the UK. No one with a normal car would change the oil every 3000 miles. The fleet market would never accept it.
I suppose that it ensures that the oil level is always topped up (providing that you trust the garage)
Like most things in life, you just need to buy something reasonable of the right grade, unless once you have read all those Google search results you can tell us what the Holy Grail of oil is.
Synthetic, semi-synthetic, and mineral are all the base oils that then have additives put in to achieve the lubrication standards required. So initially they are all pretty much the same. But they degrade with use in reverse order so Fully synthetic in theory does no degrade anywhere near as fast as mineral. It is why modern car manufacturers often state 18k miles or more between oil changes. Interestingly though they usually state 'or 12 months whichever comes first'!
Fully synthetic oil does seem to be thinner when hot compared to semi synthetic though and as a result will burn off quicker and possibly cause smoking exhausts in older or more worn engines. I would stick with whatever it says in your TVR handbook as it is a pretty good bet that whatever they chose, it was for good reason and we are not going to know any better than them!!
Fully synthetic oil does seem to be thinner when hot compared to semi synthetic though and as a result will burn off quicker and possibly cause smoking exhausts in older or more worn engines. I would stick with whatever it says in your TVR handbook as it is a pretty good bet that whatever they chose, it was for good reason and we are not going to know any better than them!!
keynsham said:
Synthetic, semi-synthetic, and mineral are all the base oils that then have additives put in to achieve the lubrication standards required. So initially they are all pretty much the same. But they degrade with use in reverse order so Fully synthetic in theory does no degrade anywhere near as fast as mineral. It is why modern car manufacturers often state 18k miles or more between oil changes. Interestingly though they usually state 'or 12 months whichever comes first'!
Fully synthetic oil does seem to be thinner when hot compared to semi synthetic though and as a result will burn off quicker and possibly cause smoking exhausts in older or more worn engines. I would stick with whatever it says in your TVR handbook as it is a pretty good bet that whatever they chose, it was for good reason and we are not going to know any better than them!!
I'm almost agree with you.Fully synthetic oil does seem to be thinner when hot compared to semi synthetic though and as a result will burn off quicker and possibly cause smoking exhausts in older or more worn engines. I would stick with whatever it says in your TVR handbook as it is a pretty good bet that whatever they chose, it was for good reason and we are not going to know any better than them!!
I say "almost" cause:
-Surely TVR reccomend the right oil BUT sometimes commercial agreements counts....
-Maybe the designer of the engine knows a thing or two about what it's creature drink.....
Malcster said:
Why is Semi-Synthetic oil often recommended for the speed six? (10w40 seems to be the general opinion)
The only real advantage to Semi over Fully-synth seems to be that it is cheaper. But not but a huge amount really.
The advantages to fully-synth surely outweigh that? Particularly for an engine that has lubrication flow issues when cold:
- It's better at withstanding hot and cold temps
- It flows better
- It produces less sludge / deposits
- It creates a more robust film at high temp / high load
Maybe I'm missing something?
Any oil gurus out there?
Powers Performance engine warranty states 'You must ensure that you use unleaded fuel octane rating RON 97/98 at all times, and use the followingThe only real advantage to Semi over Fully-synth seems to be that it is cheaper. But not but a huge amount really.
The advantages to fully-synth surely outweigh that? Particularly for an engine that has lubrication flow issues when cold:
- It's better at withstanding hot and cold temps
- It flows better
- It produces less sludge / deposits
- It creates a more robust film at high temp / high load
Maybe I'm missing something?
Any oil gurus out there?
grade of oil during and after the running in period; [0 - 1000 miles use only 10W/40 mineral oil] and [>1001 miles use only 10W/40 or 15W/40 semi-synthetic oil].'
This is why I use 10W/40 Semi-Synthetic.
Englishman said:
Andrea7 said:
Any info about the Shell Helix Hx3 20w 50 suggested by Melling?
https://www.shell-livedocs.com/data/published/en-AU/1d7fcf36-70e9-4f96-b0c4-4cac18b2ee91.pdfMaybe high viscosity and anti wear additives are key factors of Melling choice?
I'm thinking about finger followers protection....
This could drag on as a debate, but for what it is worth.
I tried 0-30, 10-40, 10-50 with zinc in a SP6, my donkey engine. All "synthetic". Pressure dropped of a bit with 0-30 but other than that no noticeable benefit or downside with the 30 Vs 50. The 30 and 40 are very thin when hot, and if you push on and the oil is hot, like F'ing hot then I don't think they are really up to it. If you cruise about then 10-40 is a good bet and if you can find a zinc rich then why not.
There is an oil grade comparison vid from the US where a flat tappet situation is simulated and 4 or 5 different oils tested, the oils are heated and other tests done. As you would expect the results show lower wear with "thicker" oils (50's etc) but don't forget flow. I know the 30 flowed well right from the start and one thing to be aware of with the SP6 is the weak oil pump shaft, the needle bearing end struggles when cold and a 50 or 60 will really test it cold when pressure is highest. My engine has been apart so many times for mods but no issues noted on crank bearings or followers with different oils.
Sorry, no definite answer....
I tried 0-30, 10-40, 10-50 with zinc in a SP6, my donkey engine. All "synthetic". Pressure dropped of a bit with 0-30 but other than that no noticeable benefit or downside with the 30 Vs 50. The 30 and 40 are very thin when hot, and if you push on and the oil is hot, like F'ing hot then I don't think they are really up to it. If you cruise about then 10-40 is a good bet and if you can find a zinc rich then why not.
There is an oil grade comparison vid from the US where a flat tappet situation is simulated and 4 or 5 different oils tested, the oils are heated and other tests done. As you would expect the results show lower wear with "thicker" oils (50's etc) but don't forget flow. I know the 30 flowed well right from the start and one thing to be aware of with the SP6 is the weak oil pump shaft, the needle bearing end struggles when cold and a 50 or 60 will really test it cold when pressure is highest. My engine has been apart so many times for mods but no issues noted on crank bearings or followers with different oils.
Sorry, no definite answer....
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