mobil 1 15/50 or 20/50

[heritage2008]

Purchased a 1977 911S Targa with 95,000 original miles. Came from San Deigo in 04 with 93,000 miles and has basically been tucked in a garage in Ohio.

Will get pics up soon--very clean car--no rust and should be numbers matching.

Just picked up this car from a PO that has let it sit for 6 years--starting it occasionally but got scared from oil leaks---I think they over filled the oil. The oil in it has about 1500 miles. I do not want to fire it up without cleaning the fuel tank and lines and changing oil.

Is it ok to pull the sending unit on top of the tank and siphon the gas out this way?

How would I go about clearing out the old fuel from all the lines without pushing crap through injectors or should I just use some Techron in tank with new gas and run it through? Was told car was driven from Michigan to Ohio and parked. Did this recently with 928 and smoothed out after only 5 minutes--it sat for same time--bought both.

The motor has had the reactors removed, valve covers done, valve adjustment done in last 2,000 miles, Carrera Oil cooler installed and a cover over the filter installed. Some oil lines were also replaced.

So, do I run the 15/50 or 20/50. Does cost make a difference--yes, but not at the expense of a rebuild. My thought is the 15/20 would not matter since it will not see days below 45/50* F. and would need the 50 for heat protection.

Is the zinc need compatible in both?

How do you tell if the tensioners were upgraded? Is this strictly an R&R to check?

This site has provided a great deal of help getting the shark on the road-now time for the Targa to find some wind.

[brads911sc]

brad penn or valvoline VR1. not mobil 1

[Arne2]

PO of my car used Mobil 1, I've switched to Brad Penn. If you plan to stick with Mobil 1, I've heard that the 20W-50 has more ZDDP than the 15W-50. But I can't confirm that of my own knowledge.

[Bill Verburg]

There is nothing wrong w/ M1, many of us use it w/o issue and have done so for decades, have they changed the formula in that time, yes, but it is still a fine oil
Mobil oil info

there are many different lines of Mobil oil, I use the 15w/50 listed second from the bottom on pg1 above, there are some that prefer the V-Twin 20w/50 listed 3rd from the bottom on pg2 because it has more ZDDP, it is a lot more expensive and the additional ZDDP is not necessary. Avoid the 0w/50 listed last it is a racing oil and will need to be changed very frequently, Avoid any ACEA A1/B1-08 rated oil

Porsche recommends M1 5w/50 listed 4 from the bottom for all Porsches ever made, but I'll stick w/ 15w/50

Nothing wrong w/ Brad Penn or any of the other boutique oils except cost and availability

[porterdog]

Shell Rotella T6 Synthetic, 5w40; $20/gal at Walmart.

~1100ppm P
~1200ppm Zn
~800ppm Ca

From Here.

[Autoban]

I picked up my '86 Cab in January. The PO used Mobile 1 15W50 Synthetic oil and I kept using it. After the first 6K Miles I had to add a quart of oil. My car does not leak and the oil pressure is stable. I have driven it at temperatures in the high 20s as well as close to 100F and the oil pressure is very stable.
As far as draining your gas tank. If you lift up your car to get to the bottom of the fuel tank you can disconnect the fuel line going to the fuel pump and let the fuel drain out. I believe there is also a filter down there, but I'm not sure.

Juergen

[Iciclehead]

Originally Posted by Bill Verburg

There is nothing wrong w/ M1, many of us use it w/o issue and have done so for decades, have they changed the formula in that time, yes, but it is still a fine oil
Mobil oil info

there are many different lines of Mobil oil, I use the 15w/50 listed second from the bottom on pg1 above, there are some that prefer the V-Twin 20w/50 listed 3rd from the bottom on pg2 because it has more ZDDP, it is a lot more expensive and the additional ZDDP is not necessary. Avoid the 0w/50 listed last it is a racing oil and will need to be changed very frequently, Avoid any ACEA A1/B1-08 rated oil

Porsche recommends M1 5w/50 listed 4 from the bottom for all Porsches ever made, but I'll stick w/ 15w/50

Nothing wrong w/ Brad Penn or any of the other boutique oils except cost and availability

I have an "in" with Exxon as my daughter works in downstream supply chain and was in lubes at one point. She put me in contact with their higher end product support people and we discussed products at length. They are painfully aware of the ZDDP issue and the effect of new legislation on lubricants and the consequence for older cars. After a lot of talking, their recommendation was the V Twin 20/50 and that is what I have gone with for my Kremer 3.2. Only side effect I can see compared to my previous Mobil 1 0w40 is that my oil pressure runs a little higher when cold but the oil fits within the Porsche recommendation, is relatively easily available (for me) and has the backing of a good company behind it.

D.

[Nick Triesch]

Porsche puts Mobil 1 in their new $100,000-$500,000 cars. Do you really think they would put in inferior oil in their super cars? No. They want their cars to be the best most reliable sports cars in the world. And they are.

[porterdog]

Originally Posted by Nick Triesch

Porsche puts Mobil 1 in their new...

Old <> new.

Heard of flat tappets?

[SilberUrS6]

Originally Posted by Nick Triesch

Porsche puts Mobil 1 in their new $100,000-$500,000 cars. Do you really think they would put in inferior oil in their super cars? No. They want their cars to be the best most reliable sports cars in the world. And they are.

Yes, but what works for modern cars might not be the best choice for our decades-old cars.

Fully-synthetic oil for the modern Porsche motor is a no-brainer. But it might not have enough ZDDP for our cars, so might not be the best choice. M1 is a good brand, and if you can get the proper viscosity and the proper additives, I say go for it.

[RSTarga]

Oils again?? All I can say is I've used 15-50w Mobil 1 in my Porsches for over 30 years in Texas heat, in Turbos and normally aspirated, MFI and electronic and I have NEVER had an oil related problem.
There may be other oils out there that are equally good but you will not go wrong with 15-50w Mobil 1, and it has sufficient ZDDP.
I think it is preferable to drain the tank at the bottom outlet and clean the filter there at the same time. That way the crap at the bottom of the tank will be flushed out. When it's empty I'd take the float out and shine a light down to see the condition of the tank. It would also be advisable to change out all your fuel hose and brake hoses too.

[bh912e]

All I know is if you track your car I would use VR1 or another quality racing oil. On every car I used on the track I noticed oil pressure drop off after a session with Mobil 1 oil. After switching my oil and taking my car back to the same track my oil pressure stayed more consistent and was highter overall. (the same weight oil was used for both brands) It almost seemed like Mobil 1 was breaking down with the rigors of racing. Maybe because it has less ZDDP then the racing oils? Either way I don't like to play games with oil pressure so no more Mobil 1 for me....

[Steve@Rennsport]

Originally Posted by Iciclehead

I have an "in" with Exxon as my daughter works in downstream supply chain and was in lubes at one point. She put me in contact with their higher end product support people and we discussed products at length. They are painfully aware of the ZDDP issue and the effect of new legislation on lubricants and the consequence for older cars. After a lot of talking, their recommendation was the V Twin 20/50 and that is what I have gone with for my Kremer 3.2. Only side effect I can see compared to my previous Mobil 1 0w40 is that my oil pressure runs a little higher when cold but the oil fits within the Porsche recommendation, is relatively easily available (for me) and has the backing of a good company behind it.

D.

JMHO, but based on experience thats the best advice in this thread.

The current M1 15/50 offering is nothing like the older API/SG stuff and for that reason, we recommend the V-Twin 20w-50 oil for owners with air-cooled engines who wish to use an M1 product. Its good stuff.

[SilberUrS6]

Originally Posted by Steve@Rennsport

JMHO, but based on experience thats the best advice in this thread.

The current M1 15/50 offering is nothing like the older API/SG stuff and for that reason, we recommend the V-Twin 20w-50 oil for owners with air-cooled engines who wish to use an M1 product. Its good stuff.

I noticed the last time I was at Autozone that there are two different bottles of V-Twin 20W50. Do you have an image of the stuff you use? Or which specification is the correct one?

Thanks.

[brads911sc]

If the new cars were the same as the old cars... we wouldnt have a standing debate. would we....

Originally Posted by Nick Triesch

Porsche puts Mobil 1 in their new $100,000-$500,000 cars. Do you really think they would put in inferior oil in their super cars? No. They want their cars to be the best most reliable sports cars in the world. And they are.

[calling911]

You need high mileage mobil 1... its got plenty of the goo.

[vesnyder]

I changed to Mobil 1 on my 20 yr old motor (at the time) and it sprung leaks from everywhere! I switched away from synthetic and back to VR-1 and most of the leaks went away. I would not recommend synthetic in an old air cooled motor.

[Scott Watkins]

Unless otherwise requested, Mike Callas at Rennsport only fills with his engines with RP.

[heritage2008]

If I choose to stay away from synthetics given the age on the motor, which Rotella makes since---15/40 Deisel?

[Eagledriver]

Originally Posted by bh912e

All I know is if you track your car I would use VR1 or another quality racing oil. On every car I used on the track I noticed oil pressure drop off after a session with Mobil 1 oil. After switching my oil and taking my car back to the same track my oil pressure stayed more consistent and was highter overall. (the same weight oil was used for both brands) It almost seemed like Mobil 1 was breaking down with the rigors of racing. Maybe because it has less ZDDP then the racing oils? Either way I don't like to play games with oil pressure so no more Mobil 1 for me....

Oil pressure is lower when the engine is hot. It doesn't matter what oil you use, this will happen. I race with M1 15-50 and change it twice a year. It's a great choice. It has over 1200ppm of Zinc. Use what makes you comfortable but there is nothing wrong with M1 15-50.

-Andy