What is a Good Synthetic Oil to Use?

I want to start using synthetic oil in my 1973 VW Beetle's T-1 engine.

What about Castrol 5 W50 for Summer time or would Quaker State be
better?
TIA

On Feb 12, 11:58*am, Jim Ed > wrote:
> I want to start using synthetic oil in my 1973 VW Beetle's T-1 engine.
>
> What about Castrol 5 W50 for Summer time or would Quaker State be
> better?
> TIA

I'm using Royal Purple 5-30 for summer. It has the older SL rating
which means more zinc than the newer SM rating. The thinner oil
allows your oil cooler to be more efficient.

On Feb 12, 3:37*pm, Robert > wrote:
> On Feb 12, 11:58*am, Jim Ed > wrote:
>
> > I want to start using synthetic oil in my 1973 VW Beetle's T-1 engine.
>
> > What about Castrol 5 W50 for Summer time or would Quaker State be
> > better?
> > TIA
>
> I'm using Royal Purple 5-30 for summer. *It has the older SL rating
> which means more zinc than the newer SM rating. *The thinner oil
> allows your oil cooler to be more efficient.

If it leaks, does Royal Purple show up better?

Was just wondering about the "5" end of the scale. Not to thin?. I put that
into my wifes Sonata and its like water!
John

John wrote:
> Was just wondering about the "5" end of the scale. Not to thin?. I put that
> into my wifes Sonata and its like water!
> John
>
>


personally, I still stick with mineral oil.
At our shop, we use Kendall GT1 20W50 mineral or Mobil 1 15W50 for all
aircooled Porsches. Mobil 1 always for race engines. I was never a Mobil
fan but I suppose it works.

I think I will use 20 W50 dino oil instead of the usual 30HD this
Summer.


On Feb 12, 6:46*pm, Jan Andersson >
wrote:
> John wrote:
> > Was just wondering about the "5" end of the scale. Not to thin?. I put that
> > into my wifes Sonata and its like water!
> > * * * * * * * * * * * * * John
>
> personally, I still stick with mineral oil.
> At our shop, we use Kendall GT1 20W50 mineral or Mobil 1 15W50 for all
> aircooled Porsches. Mobil 1 always for race engines. I was never a Mobil
> fan but I suppose it works.

On Feb 12, 7:39*pm, Jim Ed > wrote:
> I think I will use 20 W50 dino oil instead of the usual 30HD this
> Summer.
>

I don't know if that really helps or not. The dual-relief system, if I
understand it correctly, has two plungers that regulate the oil
pressure. The relief one, which I think is in the front of the
case(front being front of car) bleeds excessive oil pressure directly
back into the sump. The bypass valve OTOH is designed to divert oil
away from the oil cooler when the oil is cold, thus helping warm-up
faster.

But that system was built on the idea that oils were not multi-grade
at that time. So if you put straight 30 in there, as it warms up and
thins out, two things happen. The relief valve closes more to keep the
oil pressure up. AND the bypass valve closes, sending oil through the
cooler.

If your 20w-50 oil thickens up to approximately 50 weight as it gets
hot, which I think is what it is supposed to do, then two things
happens. The oil pressure remains relatively high, potentially keeping
the relief valve open. But that also causes the bypass valve to stay
open, preventing the oil from going to the cooler because based on the
thickness of the oil.

I could be completely wrong, and Bob Hoover would probably be a much
more authoritative source on this. But this is how I have come to
comprehend what happens as the engine warms up with straight-weight
versus multi-weight oils. As a further point of interest, the original
owners manual I have for my 74 super does not mention multi-grade oils
at all with the exception of SAW 20W-20. I have no idea what that was.
Other than 20W-20, which may have been a typo, it just lists different
temperature ranges, and the proper straight-weight oil to use from 5w
up to 40w. It also mentions service grade SD or SE as being required
for a VW engine.

Hope that helps.

Chris

On Feb 12, 4:42*pm, "John" > wrote:
> Was just wondering about the "5" end of the scale. Not to thin?. I put that
> into my wifes Sonata and its like water!
> * * * * * * * * * * * * * John

The "5W" means that it flows like 5 weight oil when it is cold and I
believe that cold is defined as 0 degrees centigrade. So if it is 70
degrees F (21C) then the oil would flow like 10 weight.

The "30" means if flows like 30 weight when it is hot (I believe 100C)

Unless it is cold outside and the oil is very thick from being cold, I
do not see any problems with 20 W 50 affecting the oil pressure relief
and control valves or bursting the oil cooler from too much pressure.

The following is from
‘More Than You Ever Wanted to Know About Motor Oil’
By Ed Hackett edh_at_maxey.unr.edu

http://www.unofficialbmw.com/all/misc/all_oilfaq.html

Multi viscosity oils work like this: Polymers are added to a light
base (5W, 10W, 20W), which prevent the oil from thinning as much as it
warms up. At cold temperatures the polymers are coiled up and allow
the oil to flow as their low numbers indicate. As the oil warms up the
polymers begin to unwind into long chains that prevent the oil from
thinning as much as it normally would. The result is that at 100
degrees C the oil has thinned only as much as the higher viscosity
number indicates.

Another way of looking at multi-vis oils is to think of a 20W-50 as a
20 weight oil that will not thin more than a 50 weight would when hot.


> I don't know if that really helps or not. The dual-relief system, if I
> understand it correctly, has two plungers that regulate the oil
> pressure. The relief one, which I think is in the front of the
> case(front being front of car) bleeds excessive oil pressure directly
> back into the sump. The bypass valve OTOH is designed to divert oil
> away from the oil cooler when the oil is cold, thus helping warm-up
> faster.
>
> But that system was built on the idea that oils were not multi-grade
> at that time. So if you put straight 30 in there, as it warms up and
> thins out, two things happen. The relief valve closes more to keep the
> oil pressure up. AND the bypass valve closes, sending oil through the
> cooler.
>
> If your 20w-50 oil thickens up to approximately 50 weight as it gets
> hot, which I think is what it is supposed to do, then two things
> happens. The oil pressure remains relatively high, potentially keeping
> the relief valve open. But that also causes the bypass valve to stay
> open, preventing the oil from going to the cooler because based on the
> thickness of the oil.
>
> I could be completely wrong, and Bob Hoover would probably be a much
> more authoritative source on this. But this is how I have come to
> comprehend what happens as the engine warms up with straight-weight
> versus multi-weight oils. As a further point of interest, the original
> owners manual I have for my 74 super does not mention multi-grade oils
> at all with the exception of SAW 20W-20. I have no idea what that was.
> Other than 20W-20, which may have been a typo, it just lists different
> temperature ranges, and the proper straight-weight oil to use from 5w
> up to 40w. It also mentions service grade SD or SE as being required
> for a VW engine.
>
> Hope that helps.
>
> Chris

"Jim Ed" > wrote in message
...

>Unless it is cold outside and the oil is very thick from being cold, I
>do not see any problems with 20 W 50 affecting the oil pressure relief
>and control valves or bursting the oil cooler from too much pressure.

bursting the cooler is less of an issue than having a 50 weight rated oil...
At operating temperature it can, and will in a healthy engine, cause the
bypass valve to remain open, or partially open, and oil will bypass the
cooler.. I used to run the 20-50 weight because everyone said it was what
vw's "needed"... they also said it didn't need the thermostat, all vw's have
****ty heat, and that it needed a relay or the starter wouldn't work... all
those things have proven to be horse**** over the years...