Fully Synthetic oil in an old car.
Discussion
mgv8 said:
People keep telling me know to use Fully Synthetic oil in my 1969 car. I think this is just as the first systhetics were to thin and did not work. Does any one know why I keep getting told this?
Because people are luddites, and can't get their head around the fact that viscosity is viscosity, whatever the base stock of the oil.If your car wants (say) 10w40, then putting 0w30 in may well result in it pissing out. Putting 0w60 in may well result in it pissing out, too, as the pressure could be too high.
That would apply whether the oil is mineral, semi-synth or full-synth. Except you don't tend to get really thin or thick minerals.
My other favourites include "Oooh, it'll dissolve the seals" and "Oooh, it'll remove all the muck that's holding the oil in"...
It's particularly entertaining for certain '80s engines which might share a bit of heritage with '40s engines, when "the experts" tell you you MUST use straight 30 or 40, not even multigrade, because anything else is too modern, when the actual owner's handbook recommends synthetic...
mgv8 said:
People keep telling me know to use Fully Synthetic oil in my 1969 car. I think this is just as the first systhetics were to thin and did not work. Does any one know why I keep getting told this?
It has nothing to do with viscosity. Unless your car has been converted to fuel injection with valve stem oil seals and a closed loop, i.e. lambda sensors, management system you must not use fully synthetic oil. It has no capacity to deal with fuel contamination which is inevitable on a car running carbs. It will break down very quickly and slowly ruin the bearing surfaces of your engine.On cars with early injection systems or very efficient carbs such as the German Solex 4A, semi-synthetic is allowable, as it can deal with fuel cpontamination to a certain extent.
J
jith said:
It has nothing to do with viscosity. Unless your car has been converted to fuel injection with valve stem oil seals and a closed loop, i.e. lambda sensors, management system you must not use fully synthetic oil. It has no capacity to deal with fuel contamination which is inevitable on a car running carbs. It will break down very quickly and slowly ruin the bearing surfaces of your engine.
On cars with early injection systems or very efficient carbs such as the German Solex 4A, semi-synthetic is allowable, as it can deal with fuel cpontamination to a certain extent.
J
Meanwhile : http://blog.amsoil.com/how-does-motor-oil-become-c...On cars with early injection systems or very efficient carbs such as the German Solex 4A, semi-synthetic is allowable, as it can deal with fuel cpontamination to a certain extent.
J
jith said:
It has nothing to do with viscosity. Unless your car has been converted to fuel injection with valve stem oil seals and a closed loop, i.e. lambda sensors, management system you must not use fully synthetic oil. It has no capacity to deal with fuel contamination which is inevitable on a car running carbs. It will break down very quickly and slowly ruin the bearing surfaces of your engine.
On cars with early injection systems or very efficient carbs such as the German Solex 4A, semi-synthetic is allowable, as it can deal with fuel cpontamination to a certain extent.
How's the weather on your planet?On cars with early injection systems or very efficient carbs such as the German Solex 4A, semi-synthetic is allowable, as it can deal with fuel cpontamination to a certain extent.
steveo3002 said:
been using it for years in my old cars , no problems
think the tales have come from the same lot that still buy cellulose paint and crossplys...you have to move with the times
It has nothing to do with moving with the times. If you're driving an old car with the original engine, fuel and ignition setup you are not "moving with the times", you are utilising old technology. You should therefore run the engine in harmony with that technology. All the major oil companies now produce better quality oils for classic cars which is moving with the times. None of them are fully synthetic.think the tales have come from the same lot that still buy cellulose paint and crossplys...you have to move with the times
Edited by steveo3002 on Wednesday 15th June 10:41
This is my experience based on well over forty years experience in engine technology.
For those who live on the planet Zanussi, and drive stinky 2 cylinder rot boxes, the best of luck with your engines.
J
jith said:
steveo3002 said:
been using it for years in my old cars , no problems
think the tales have come from the same lot that still buy cellulose paint and crossplys...you have to move with the times
It has nothing to do with moving with the times. If you're driving an old car with the original engine, fuel and ignition setup you are not "moving with the times", you are utilising old technology. You should therefore run the engine in harmony with that technology. All the major oil companies now produce better quality oils for classic cars which is moving with the times. None of them are fully synthetic.think the tales have come from the same lot that still buy cellulose paint and crossplys...you have to move with the times
Edited by steveo3002 on Wednesday 15th June 10:41
This is my experience based on well over forty years experience in engine technology.
For those who live on the planet Zanussi, and drive stinky 2 cylinder rot boxes, the best of luck with your engines.
J
Maybe I should try a fully synthetic oil at the next oil change
jith said:
It has nothing to do with moving with the times. If you're driving an old car with the original engine, fuel and ignition setup you are not "moving with the times", you are utilising old technology. You should therefore run the engine in harmony with that technology. All the major oil companies now produce better quality oils for classic cars which is moving with the times. None of them are fully synthetic.
This is my experience based on well over forty years experience in engine technology.
For those who live on the planet Zanussi, and drive stinky 2 cylinder rot boxes, the best of luck with your engines.
J
Here is one:This is my experience based on well over forty years experience in engine technology.
For those who live on the planet Zanussi, and drive stinky 2 cylinder rot boxes, the best of luck with your engines.
J
http://www.opieoils.co.uk/pv-119186-millers-oils-c...
We still seem to have a split view. I think some of it is from the old 0-20 stuff that would be way to thin for old cars. But now we can get 20-50 what is the problem??????
Quite a few years ago Mobil introduced its fully synthetic oil AV1 for aircraft engines. It stayed on the market for almost 3 years and was withdrawn on the back of a legal claim in the US for damage caused to the engines it was used in.
Aero engines typically are air cooled and Avgas has a huge amount of lead in it. The AV1 was not holding the lead in suspension and getting burnt off as with the traditional monogrades. Instead it caused a sludge which built up in the engine bearings.
Car engines are not subject to the same issues but I think the critical aspect is matching the viscosity the engine and most particularly its clearances were intended to use. The modern oils are undoubtedly 'better' in terms of lubricity and dealing with contamination, but they need to same level of viscosity to maintain pressure and not have high consumption.
With that I'd be happy using modern oil, and indeed I do, one with specific additives to reduce scuffing wear, typically on bucket tappets.
Aero engines typically are air cooled and Avgas has a huge amount of lead in it. The AV1 was not holding the lead in suspension and getting burnt off as with the traditional monogrades. Instead it caused a sludge which built up in the engine bearings.
Car engines are not subject to the same issues but I think the critical aspect is matching the viscosity the engine and most particularly its clearances were intended to use. The modern oils are undoubtedly 'better' in terms of lubricity and dealing with contamination, but they need to same level of viscosity to maintain pressure and not have high consumption.
With that I'd be happy using modern oil, and indeed I do, one with specific additives to reduce scuffing wear, typically on bucket tappets.
If you're in doubt why not contact the oil manufacturer ?
Several years ago I contacted Castrol who advised me not to use fully synthetic oil in my Jaguar engine. They recommended a semi-synthetic or a mineral oil.
I note they still offer an advice service.
http://www.castrol.com/en_gb/united-kingdom/produc...
When I worked in the Marine Industry several machinery manufacturers recommended that synthetic oil wasn't used until the relevant equipment had been "run-in"
Several years ago I contacted Castrol who advised me not to use fully synthetic oil in my Jaguar engine. They recommended a semi-synthetic or a mineral oil.
I note they still offer an advice service.
http://www.castrol.com/en_gb/united-kingdom/produc...
When I worked in the Marine Industry several machinery manufacturers recommended that synthetic oil wasn't used until the relevant equipment had been "run-in"
Edited by mph on Wednesday 15th June 15:36
mph said:
When I worked in the Marine Industry several machinery manufacturers recommended that synthetic oil wasn't used until the relevant equipment had been "run-in"
I've heard that quite a few times - with the logic being that the better-quality oils don't allow the initial bedding-in wear. In other words, they're too good at preventing wear.I'm not convinced that's a bad thing, 99% of the time...
mph said:
If you're in doubt why not contact the oil manufacturer ?
Several years ago I contacted Castrol who advised me not to use fully synthetic oil in my Jaguar engine. They recommended a semi-synthetic or a mineral oil.
I note they still offer an advice service.
http://www.castrol.com/en_gb/united-kingdom/produc...
When I worked in the Marine Industry several machinery manufacturers recommended that synthetic oil wasn't used until the relevant equipment had been "run-in"
Thanks that was a good read.Several years ago I contacted Castrol who advised me not to use fully synthetic oil in my Jaguar engine. They recommended a semi-synthetic or a mineral oil.
I note they still offer an advice service.
http://www.castrol.com/en_gb/united-kingdom/produc...
When I worked in the Marine Industry several machinery manufacturers recommended that synthetic oil wasn't used until the relevant equipment had been "run-in"
Edited by mph on Wednesday 15th June 15:36
I don't run synthetic on my Land Rover, not due to any concerns over compatability, but just because it probably doesn't make any financial sense to do so. So it gets cheap mineral oil. If someone produced a 20W50 synthetic as cheap as the mineral stuff I use now, it'd get that instead.
I think this is perhaps where a certain amount of the "common knowledge" gets a bit skewed, in that for a lot of cases, there's no reason to choose synthetic oil for a "classic" engine, but that doesn't mean you should actively choose not to. Strikes me as something that very much depends on the case concerned, what engine, what state it's in, and how you use it.
The concept of "classic oils" probably isn't a scam, though. I'd assume that they have a different additive content to allow for the needs of older engine designs.
I think this is perhaps where a certain amount of the "common knowledge" gets a bit skewed, in that for a lot of cases, there's no reason to choose synthetic oil for a "classic" engine, but that doesn't mean you should actively choose not to. Strikes me as something that very much depends on the case concerned, what engine, what state it's in, and how you use it.
The concept of "classic oils" probably isn't a scam, though. I'd assume that they have a different additive content to allow for the needs of older engine designs.
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