Which oil

johnymd

johnymd

Club Member
Oil seams to be a complex subject with lots of varying opinions that are often not base on fact or lab testing. So, I've spent a few hours reading and I'm still none the wiser. I've come to the conclusion that I want a true synthetic and not the dino based stuff thats got fully synthetic on the label so that narows it down quite a bit. The engine is originally run with 10-40 but that was 20 years ago so thing have probably changed a bit. I've seen people recommending 0-30 for road and 0-40 for track and lots of people using 10-40. Am I just worying about it too much and should just go with the manuafacturers recommendation?
 
tel240z

tel240z

Club Member
do you have an oil temp guage john ?

IMO its all about how the oil gets there in the morning and how it stands up to high temps, as i have said in another thread from experience i used to run 10 litre diesel engines on mineral oil for 80,000 miles between changes and a 1000,000 miles later still running fine, if i was you i would use at leas,t a something /40 and knowing your engine and how extreme it has to work i would use as you say a proper synthetic 5/50 cos i know it goes out in the cold frosty mornings so you need that low viscosity number to get it round when cold, i suspect your oil temps get high around 230-260 degrees so the 50w would be good
 
7

73dattoDD

Forum User
johnymd said:
Oil seams to be a complex subject with lots of varying opinions that are often not base on fact or lab testing. So, I've spent a few hours reading and I'm still none the wiser. I've come to the conclusion that I want a true synthetic and not the dino based stuff thats got fully synthetic on the label so that narows it down quite a bit. The engine is originally run with 10-40 but that was 20 years ago so thing have probably changed a bit. I've seen people recommending 0-30 for road and 0-40 for track and lots of people using 10-40. Am I just worying about it too much and should just go with the manuafacturers recommendation?
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no synthetic can compare to pure refined.

Penn grade 1 oil is the best oil you could buy. Its green in color and high in zinc and phosphates with many applications. it will possibly even gain you a few hp. i dont think it is good for cat's but, they have oil to suit your needs
 
johnymd

johnymd

Club Member
Thanks for all the advice. I'm trying to make the right choice based on current oil technology rather then just using what was considered to be the best oil for this engine in the late 80's/early 90's. I've read some really good articles which explain why you should use a 0-30 or 0-40 and why the numbers aren't a good indication of the viscocity of that oil. Trouble is most of the articles went on and on and I got bored so didn't read it all. I've read that there ore only a few true synthetic (redline, royal purple, castrol german and a few others) and that Mobile has gone downhill.

Can someone tell me what the numbers mean because the last article I read states that they are not the viscocity.
 
racer

racer

Club Member
I'm no expert John but I believe the numbers refer to the cold and hot temperature viscosity i.e.

The 10w or 10 Winter viscosity would be thicker in the cold weather therefore not as good as 5w in the cold.

The 2nd figure say 40 is the minimum viscosity at 100deg.

The better the quality the lower the 2nd figure can be
so a typical good quality synthetic would be 5/30
Your engines pretty modern so I would think 5w 30 quality synthetic would be ok.
No cat to worry about so you can go for something with more SAPS.
Bit of a minefield really
 
Mr.F

Mr.F

Inactive
Mobil has gone downhill
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IMO they were never up the hill in the first place. Their 0W runs like cat's p*ss when hot...
Millers 5W-40 works great in the Nissan V6 engines. Some of the heavy duty turbo engine owners often use the Competition synthetic 10W-60.
Both in stock...
 
T

Throttleton

Well-Known Forum User
I asked the father in law for some help/info on oil for the engines mentioned, hope it helps,


Hi Craig,
with no catalytic converters to worry about the oil performance quality suitable for these engines will be API/SF or API/SG or newer. The engines were probably developed using API/SF but that old technology is probably not available these days; but that will not matter since the newer technologies build enhanced performance features. As for viscosities then for non-extreme climates SAE 10W40 is the best bet although SAE 5W40 products can be good also for very cold starts in particular and SAE 20W/40 for warm winter countries.
The API quality defines the oil additive performance level (ie detergents,dispersants,antioxidants) and the SAE Viscosity performance at winter temperatures eg 20W or 10W or 5W and operating temperature eg @100 degC SAE 30,40,50.
The only other issue is the lubricant base stock which is the carrier fluid (oil) into which the additives are blended ie. API performance additives and SAE viscosity index improvers to give multigrade characteristics. It is worth knowing that sometimes the purest base stocks can be the most difficult to treat. However a synthesised hydrocarbon or semisynthetic base stock product with strong API performance additive packages make good lube oils for these type of engines and exotic lubricating fluids are unnecessary as a general rule.
Finally do not underestimate the value of regular oil changes whatever product you are using in order to replenish the oil performance chemistry which naturally degrades with time and with use. With higher oil consumption engines some replenishment is being achieved by oil top ups and has a beneficial effect to be taken into account.
As a general principle it would be better to half the oil change period than pay twice the price for an oil providing you take care in what you buy in the first place! Look for API and SAE as mentioned above which are USA organisations; (there are some European ones such as Mercedes Benz but lets not overcomplicate matters.)
 
tel240z

tel240z

Club Member
Yes very good write up there! i know i,m old school but i change my oil in all my kit far to often but thats because i can ;) i'm not surprised oil is an issue as Barb indoors runs a seat leon TDI which has the VW 1.9 engine in the same as the golfs/passats and T5 transporters, now the VW servicing regime can be long drain 20,000 :eek: miles using the right oil or 10,000 using normal life but the Seat regime has no option for the long drain interval so i just use the long drain and change it every year about 8,000 miles just to add iv'e never had a siezed engine :cool:
 
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