Running full sythetic in a classic car?

[FCD]

Soo i still haven't decided what oil to use for the next oil change this summer for my Ford Capri, these are the oils i'm considering:
Valvoline VR1 20w50 Mineral
Valvoline VR1 10w60 Syn-blend
Castrol Power 1 15w50
And the latest i'm considering : Mobil 1 15w50 Full synthetic motorcycle oil, i've heard this oil has great shear stability, low volatility and high zddp , being a full synthetic i'm a bit worried that it could make my engine leak like crazy and make it burn lots of oil since mine has run on conventional or syn-blends for most of it's life, it's also expensive since it costs around 50 Euros for 5 liters here, but obviously the advantage is that i could extend oil change intervals to longer than 1 year right? what's your opinion?

 

[SR5]

I've run full synthetics (Castrol Edge 10W-60) in older cars ( eg 80's era) without problem. No sudden leaks or consumption issues. The oil just seemed to stay cleaner looking for longer.

 

[Olas]

Originally Posted By: SR5
I've run full synthetics (Castrol Edge 10W-60) in older cars ( eg 80's era) without problem. No sudden leaks or consumption issues. The oil just seemed to stay cleaner looking for longer.


+1

Leaks and consumption are down to gaskets, rings and stem-seals - they either seal or they don't.

 

[Lapham3]

For me, the answer is the old- 'it depends. On the 30-50 year old cars, it depends on how much history I know about use and maintenance. I will use a syn where I've been inside the engine for any rework/repairs and it's now clean and I know it's condition. If I haven't, as with a likely/possibly sludge,ect I likely wouldn't.

 

[zeng]

I would consider fully synthetics only if promotional price (if any) is attractive......
or engine is turbo'ed ....
or with high compression ratio ....
which doesn't quite apply in your case.

 

[Jimzz]

If the engine has been rebuilt and has newer seals/gaskets then maybe.

But since it seems you do not drive much I would lean toward a good oil like a 15w40, what I run in my 73 Chevy, and change it once a year. I run 4qts of 15w40 and 1 qt of High mileage xW30.

 

[FCD]

Nah my engine hasn't ever been rebuilt nor does it have a turbo or high compression , but the idea of a 15/20w50 full synthetic oil really sounds good to me , i won't run a 15w40 since with 10w40 it burned quite a bit of oil and 20w50 is what is specced for this engine, soo do you think i should do it or just stick to a quality mineral 20w50 like VR1?

 

[Doog]

Syn in a pre-1993 car...no way

 

[kschachn]

Originally Posted By: Doog
Syn in a pre-1993 car...no way


I've run synthetic in all my cars since 1979, please tell what should have happened? An why that year? Looks like I just escaped danger on my '94 BMW.

 

[Pepsibottle1]

Perfectly fine. The suggestion that synthetic oil causes leaks though is pretty false, I just find it exaggerates existing seepage if you have them. Synthetic is nicer to being sat in an engine too as is the case with classic cars but honestly you don't need it. NAPA brand dino is just fine

 

[Bookmaker]

Ridiculous not to use synthetic. Just be sure it has enough zinc for the old flat-tappet engines. I run Rotella T6 5w40 in my 1974 318 Duster and in my daughter's 1969 Karmann Ghia. It is doing well in both cars.

 

[chrisri]

Originally Posted By: FordCapriDriver
Nah my engine hasn't ever been rebuilt nor does it have a turbo or high compression , but the idea of a 15/20w50 full synthetic oil really sounds good to me , i won't run a 15w40 since with 10w40 it burned quite a bit of oil and 20w50 is what is specced for this engine, soo do you think i should do it or just stick to a quality mineral 20w50 like VR1?


As you probably know most synthetics of today are GIII, most certainly in thicker grades. So yes, you can use synthetic in Capri, it could even benefit since it will have lower NOACK.

Just avoid PAO, and Ester based synthetics', they are not good for oil burning engine.

 

[Pontual]

Well if it leaks with 15w50, you need to face the job, anyway.

 

[OneEyeJack]

Several people around here swear by Red Line 20w-60 motorcycle oil in their antique vehicles. They have zero problems with the oil causing new leaks. Some of these engines leak no matter what you do and it's not because of the synthetic oil. That just the way things were in the good old days.

One of the cars, a Pierce Arrow has a notebook that came with the car. It lists all the dimensions used by the mechanic that assembled the engine using aged block and head castings. He bored and honed the cylinders, machined all the surfaces and carefully hand assembled the complete engine. The engine was first started and run while mounted in the chassis until it was evident that the rings were seated. It was then driven for about 100 miles on a test track and finally torn down, re-measured and re-fitted as necessary for final assembly and delivered to the new owner. After the car was driven about a thousand miles by the new owner it was again partially torn down, checked and reassembled. It was then checked every thousand miles after that with an oil change and if needed, the head removed for carbon scraping and a change of spark plugs.

The notebook also contains information on how to contact the mechanic that built the engine and other people that assembled the chassis and running gear. The transmission and differential were also torn down during this process to be checked and refitted as needed.

All this probably explains why there are no Pierce Arrow cars, today.

This car today is still running on that original build but now uses Red Line 20w-60 engine oil and modern green coolant with distilled water changed once a year in place of tap water and alcohol that was also flushed every thousand miles.

 

[Olas]

Originally Posted By: Doog
Syn in a pre-1993 car...no way


Why not?

 

[FCD]

I know the myth about synthetics causing oil leaks is false, what i mean is that it might clean up the gunk and sludge that is keeping the seals and gaskets from leaking, at the moment running 20w50 it doesn't leak, didn't leak on 10w40 either, it kinds sucks thhat here in Europe we don't have a lot of high viscosity full synthetics like in America where you can find 20w50 oils in full synthetic like Royal Purple , Amsoil, Redline etc... it looks like this oil is a PAO based oil though so i might stick to a quality mineral 20w50 to be safe and do fairly frequent oil changes

 

[Shipo]

Originally Posted By: Doog
Syn in a pre-1993 car...no way


Sorry Doog, bad statement of the day award. Many of us started using synthetic oil back in the 1970s and never had issues; for my part I used it in my (then) new 1979 Scirocco.

 

[steveh]

Originally Posted By: Olas
Originally Posted By: Doog
Syn in a pre-1993 car...no way


Why not?
In the early 90's I used synthetic in three new cars and had nothing but problems. Had many seals and gaskets replaced under warranty. Used it in a 3.1 Chevy, Dodge 2.2 turbo and a Mitsubishi 1.5. All started leaking after about six months. Never tried it again until my 2008 Corolla and it never gave me a problem. Don't know if it was the seals and gaskets in that era or if the oil was mostly PAO in that era.

 

[Boss302fan]

VR1 is what I would run if it was my car... I have owned numerous classic cars for years and VR1 has always worked well. Shell Rotella has also been a good one... If you had a moderate oil leak, then I would get it repaired.

 

[Shipo]

Originally Posted By: steveh
Originally Posted By: Olas
Originally Posted By: Doog
Syn in a pre-1993 car...no way


Why not?
In the early 90's I used synthetic in three new cars and had nothing but problems. Had many seals and gaskets replaced under warranty. Used it in a 3.1 Chevy, Dodge 2.2 turbo and a Mitsubishi 1.5. All started leaking after about six months. Never tried it again until my 2008 Corolla and it never gave me a problem. Don't know if it was the seals and gaskets in that era or if the oil was mostly PAO in that era.


Hmmm, makes no sense; I ran Mobil 1 in my 1985 Daytona Turbo for over 100,000 miles; never had a leak and never had a turbo issue.