porcho heat

Hey, about to do my first change on my 968 engine since the rebuild, right now I'm running 5w40 Mobil 1 synthetic as my mechanic suggested, but was wondering what other brands I should consider?

Redline? Royal purple? Motul? etc. and weight? Car is only driven between april and october, where the lowest temperature would probably be 5ºC on a cool day, and highest would be 41ºC or so.

What amount does the 968 engine take? Same as my old 2.5? I would usually buy 7 litres for the 2.5, 5.8 to put in and 1.2 or so to top up (it had a slow leak, my new engine is so far leakless)

Thanks for your help and suggestions

RajDatta

Jerry, most of us use 15W50 weight oils. In your case, the range is somewhat restrictive. Hopefully Dave G will chime in. He works for an oil company and has offered excellent advise in the past.

Raj

Stephenwz968

Jerry,

Right now I'm running 20w50 Castrol GTX, to try and minimize a lower balance shaft leak. I use about 6.5 quarts when changing the oil/filter. Dave G will hopefully chime in....

Steve

SuperMattyP

I have used Royal Purple with much success in previous turbo/supercharged vehicles. Typically in NA vehicles I stick with Mobil1. I think I will just spring for the Royal Purple since I'd like to have the very best in the new toy. I'll check with the previous owner as to what type of oil he has been running.

porcho heat

It's a summer car and I think I'd prefer a synthetic oil as this engine was freshly rebuilt before I swapped it... I figure this is one of the better applications for synthetic rather than using it on a tired engine...

I've either been running 5w40 or 15w40 Mobil 1, I can't recall, and oil pressure seemed to be good (As far as my 1983 oil pressure guage shows) I've only had a ticking noise once when the car hadn't started for a week and the temp was cold... so I guess this is a good weight to run?

I've heard some things about Mobil 1 not being completely synthetic anymore, and I've heard some things about Royal Purple as well... any other syn. oils with good results?

Lemming

I run non-syn Rotella T. If it can handle the abuse of a turbo-diesel engine, than it should work in a 968 engine

mikew968

I use Amsoil 20w-50 and perfer it to M1. I use less oil and seems to hold a little more oil pressure when hot. It is fully synthetic as well.

Mike

SuperMattyP

what is the OE oil used in the vehicle and the weight? I like to run the thinnest oil I can get away with but being in alabama during summertime I'm not opposed to running a 50weight if needed. If I could stay with a 40 weight I'd feel better.

Jason Judd

I've heard some stuff about Mobil-1 not being a true synthetic, too...

That being said, I still use it...15/50 for my car and I've not had any problems.

My car has a larger oil cooler, so I hold about 9 quarts of oil.

Jason

SuperMattyP

Here's the deal with synthetic oils. Not many oil manufacturers use 100% synthetic oils. Most "synthetic" oils still have a petroleum base but only synthetic additives to help control heat dissipation, reduce foaming, detergents, etc.

Royal Purple and Amsoil (that I know of) are the only 100% true synthetics meaning everything in them is man-made and contains no petroleum base.

So, YES Mobil1 synthetic is NOT a full synthetic, but it's still a high quality oil. One of the major reasons I like Royal Purple in my turbo cars is because it won't coke up bearings if it overheats. Royal Purple, when heated beyond it's limits, will turn into an ash. The second liquid oil touches it it reverts back into oil. Pretty neat feature. When I upgraded the turbo on my last car I disassembled everything and the bearings inside looked flawless. I attribute it to the oil more than anything else.

Jason Judd

SuperMattyP wrote:

"One of the major reasons I like Royal Purple in my turbo cars is because it won't coke up bearings if it overheats."
_________________________

What does it take to overheat Royal Purple...more than 250~260 degrees? Probably more than that, right? I'm guessing that it has a better abiltiy to handle the heat? Is it much more than Mobil 1?

Thanks,

Jason

PorscheDude1

I run royal purple 20/50.

stolarzj

Redline Oil is also another full synthetic. Someone on another board had a discussion with them about the proper grade for our car and they felt that 15w50 was only really necessary for really hot race type conditions. There 10w40 would be the best match for our car with there oil. It's not cheap, but cheaper then some of the others, it can be found for $8 a quart. I currently use Mobil1 15w50 and will be switching to Redline 10w40 soon.

ltc

FWIW, my dealer put Mobil 1 0W-40 in my 968 Cab when it was in for service last year.

porcho heat

Update, for what it's worth... Decided to try 15w40 Royal purple... Seems to be running fine with steady oil pressure, but I'll put on a few more kms and some longer trips and watch the gauge.