ahsan127

Hi,

Just got my 91 S2 with 75 K on it. I'm going to be using it as a commuter and will put aroung 140 miles / day on it. The previous owner drove it 1000mi/year and used regular oil. The only reason I want to switch to synthetic is that I will have to do less oil changes. Is it advisable to switch to synthetic when the car has been running on regular?

Thanks
sonny

83na944

Opinions vary, to put it mildly.

Check this thread https://rennlist.com/forums/showthre...hreadid=138646

Silverbullet951

I've always used synthetic. No problems..

alpenweissisnice

I switched from Dino juice to Mobil One and have been impressed. My car was dry before, but no new leaks. If you have a compromised seal, it may create issues, but the increased flow characteristics and the detergent action are great. I was amazed at how dark my oil was after just 1000 miles; apparently it really cleans up any sludgy build up.

Go for it!

Porsche-O-Phile

YES!

volv4life

yes.

jim944s2

I switched my 944S2 to M1, -no problems. I still change 2x a year, even with low miles. I just figure that if there's ANY benefit in longevity, it is well worth the extra $50 a year.
Actually, you'd probably recoup your costs if you resell the car, as most potential buyers would prefer a car that has been kept on synthetic, wouldn't you?

Chris_924s

yes.

Look at the archives- everyone who is using Mobil1 is very pleased.

Doug Hillary

Hi Sonny,
this thread may be of interest to you;

http://www.landsharkoz.com/techtips.htm

Look under "Lubricants for the 928"

Best of luck

944T4ME

What if my 951 engine only has 18k on it? I've always used Castrol GTX 10w40 on all my other turbo cars, and now its time to change this one's oil. Its not going to have any buildup or longevity issues cause of the low mileage. All bearings and rings are new. Does synthetic really matter if I stick to 3000 on the GTX?

Porsche-O-Phile

Synthetic will keep it running as if it has 18k on it when it has 218k on it. Seriously, the advantages of synthetic are well-documented. My preferences:

(1) Amsoil (going in my car at next oil change)
(2) Royal Purple (available at NAPA - good stuff, used in my truck)
(3) Redline Synthetic (some people swear by this)
(4) Mobil 1 Synthetic (in my car now - good stuff)

I believe only Amsoil has full 100% synthetic composition including all the binders, but the others are excellent as well and should allow you to last 8-10k between oil changes without an issue, depending on how nasty your filter is. I typically change out at 5k intervals on synth. oil just because I'm paranoid, but some people have run as long as 15k between changes with seemingly no problems on these cars.

Doug Hillary

Hi,
you might like to do a search on the 928 Forum under "Oil Condition Report" No's 1 thru 7 for an idea on how oils really survive in Porsche liquid cooled engines.

This is a series of seven used oil analysis reports using two different viscosity lubricants. The "testing" has been underway now for about 20 months. The current one in use is Mobil's Delvac 1 5w-40 - this is a "mixed fleet" HDEO and a most suitable lubricant.

Most Tribolgists believe it to be the very best engine lubricant available. It is also now sold in NA as Mobil 1 SUV 5w-40. No hype no BS just an extremely good product

Porsche-o-Phile - Amsoil's products vary by "model" as to their make up and they are not very different from most other Group 3, Group 4 or Group 5 engine lubricants. They are certainly not "better" in any sense than many others in these three Groups - and they are not as good as some by a long way!
Mobil's "SuperSyn" range are at least as good as Amsoil's very best as an example

Always check that the viscosity of any lubricant used is correct for your vehicle

Regards

Porsche-O-Phile

Thanks for mentioning that, I'll check into it. I've heard nothing but accolades for amsoil to this point though on several forums, and 5w40 sounds like it's a bit of an odd viscosity, although certainly no reason it couldn't work in these cars for particular operating temperature ranges. . .

I can't say I'm disappointed in the Mobil 1 either (I'm currently on 15w50), but I figure the "weak link" is the non-synthetic components, minimal though they may be. I'll definitely go back and do some more digging based on this information though.

944T4ME

I dont follow the synthetic oil weights, cause I know they dont quite mean the same thing.

What mobil 1 would you recommend for my car:

951, 18k on engine
280-300hp
driving style--mostly normal to slightly spirited driving, with full throttle maybe once every 20 miles. No autox.
milwaukee, wi, so might see temps as low as 30s (hey it is 55 here now!). Will never see temps over 95, though summers are quite hot and humid, usually around 85-90.

New turbo as well at same time as engine, not sure of the oil lines, if they are old and gummed up or what.

Anyone give some advice?

IceShark

Porsche-O-Phile, you might want to go and do a search of what is now the Google groups, like rec.autos.tech I recall from some years ago that Amsoil never was tested and certified by SAE or whoever does that stuff. There were quite a few fights over how important this was with the Amsoil supporters saying the only reason they didn't go through the testing was due to the cost involved and the detractors saying it was because the oil would never pass muster.

I really don't know what the truth is but the fights were enough for me to just go with M1. Life is too short to try and become an oil expert for the 10 gallons I use per year.

ahsan127, as best as I can figure out the problems with switching to a synthetic is that the superior cleaning abilities remove crap that is built up on the seals and gaskets. And they then start to leak because the gunk isn't clogging the leak areas anymore. So whether you will start to leak depends on the condition of the seals. And switching back to dino oil may not stop any leaks which might occur as the crud which used to seal things up is gone.