Synthetic oil & gear lube recommendation 944 & 928
Discussion
I've posted this stuff before in other forums, so if you've seen it there in the past, sorry, I just wanted to share it here too.
First of all, I’m not an Amsoil employee, nor do I sell this stuff. I’m an enthusiast.
My 928 now has both of the products noted below. I noticed no difference in the way the motor ran on Amsoil versus Mobil-1, but the Amsoil gear lube is real good stuff. Since it made such a difference on the way my 944 ran, I tried it on the 928 5-speed transaxle too, and it works well, but not as big a change as in the 944, perhaps due to wear and condition.
My 944 has 165,000 miles on it and had a whine in the rear end transaxle. I’m not sure what kind of lube was in it, I suspect it was Swepco. I changed the fluid with the 75W90 Amsoil synthetic gear lube, GL rated for the 944 of course, and it was almost as good as a rebuild. It stopped the whine and I can shift the car when cold just as easily as I could before when it was hot. Pretty good stuff and I recommend it. I understand Red Line makes a good synthetic, but since I have not tried it, I can only recommend what worked for me. This gear lube made a big difference in the way the car sounds internally, and in the way the transmission shifts. Good stuff for sure.
www.amsoil.com/products/prodpics/tgr.jpg
www.amsoil.com/products/tgr.html
I also tried their motor oil, and the Series 2000 synthetic is rated better than anything else I know of. It is not cheap, around $8.40 per quart or so, but if you want the best, this is close to it. My 944 was shuddering under the 20W50 so I bumped down to a lighter weight and it “seemed” to help, although I have no idea if it was the oil or not. I suspect not. I could not tell any difference in the way the car ran, as I had been running Mobil-1 and may go back to that. However, the Amsoil tests out better.
www.amsoil.com/products/prodpics/2003/tro_bottle_600pxh.jpg
www.amsoil.com/products/tro.html
regards from Nashville
SmileWavy
P
First of all, I’m not an Amsoil employee, nor do I sell this stuff. I’m an enthusiast.
My 928 now has both of the products noted below. I noticed no difference in the way the motor ran on Amsoil versus Mobil-1, but the Amsoil gear lube is real good stuff. Since it made such a difference on the way my 944 ran, I tried it on the 928 5-speed transaxle too, and it works well, but not as big a change as in the 944, perhaps due to wear and condition.
My 944 has 165,000 miles on it and had a whine in the rear end transaxle. I’m not sure what kind of lube was in it, I suspect it was Swepco. I changed the fluid with the 75W90 Amsoil synthetic gear lube, GL rated for the 944 of course, and it was almost as good as a rebuild. It stopped the whine and I can shift the car when cold just as easily as I could before when it was hot. Pretty good stuff and I recommend it. I understand Red Line makes a good synthetic, but since I have not tried it, I can only recommend what worked for me. This gear lube made a big difference in the way the car sounds internally, and in the way the transmission shifts. Good stuff for sure.
www.amsoil.com/products/prodpics/tgr.jpg
www.amsoil.com/products/tgr.html
I also tried their motor oil, and the Series 2000 synthetic is rated better than anything else I know of. It is not cheap, around $8.40 per quart or so, but if you want the best, this is close to it. My 944 was shuddering under the 20W50 so I bumped down to a lighter weight and it “seemed” to help, although I have no idea if it was the oil or not. I suspect not. I could not tell any difference in the way the car ran, as I had been running Mobil-1 and may go back to that. However, the Amsoil tests out better.
www.amsoil.com/products/prodpics/2003/tro_bottle_600pxh.jpg
www.amsoil.com/products/tro.html
regards from Nashville
SmileWavy
P
First of all, anyone on this earth who thinks they know everything about everything is a fool, and that certainly includes me.
Having said that, I can tell you that I've been using synthetic oil in my 1984 944 (165,000 miles)for the last 30,000 miles and the car loves it. I run Mobil-1 15W50 summer and go a little lighter in winter.
I've run the same oil in my 1983 928 and it loves it. Presently the 928 is using Amsoil 20W50 and loves that too.
My 1990 S2 is on Mobil-1 15W50.
My Wifes 20-v 5-cyl Volvo turbo is on Mobil-1 15W50.
My twin 427 Ford powered yacht is on Mobil-1 15W50 and those motors love the stuff.
I did some research for the Antique and Classic Boat Society, here in the US, to see if synth oil was compatible with true antiques, some of which have WW-I engines like the Liberty, etc., etc.
On the really old stuff you should use a blend, in order to get the best of both worlds.
On anything from the mid 1960's on up, you should be fine with synthetic. When synthetics first came out, they did have some problems drying out vinyl seals, because they did not have any or enough esters in the formuals, but those years are LONG GONE. Any newer engine such as the 944 will absolutely love the stuff.
Aircraft are not supposed to use a 100% synthetic due to the fact that av gas uses real lead, and synthetic will not act as a solvent for the lead additives, and will create a gum; therefore you will see blends used in aircraft piston engines for that reason.
The main benefits from synthetic oils are better flow when cold, better film strength, less breakdown of viscosity, more resistance to heat, and "no ash" when it burns.
Because of the better flow, if you have an oil leaker now, you know, a car that leaves a puddle on your driveway, then you don't want to switch to synthetic because it will flow out the leak faster than what you're using now. Otherwise there is no harm at all to an engine. Just drain and refill.
Porsche uses Mobil-1 for their initial fill.
I noticed on my 944, that after is sits up for a week or so, it will smoke when I fire it up. I attribute this to the synthetic oil slowly seeping into the valve guides and smoking when I start the car. This goes away immediately, and does not occur on a daily basis when I drive the car, it only happens when I let it sit for a week or more.
As for the marine 427 Ford motors, I like the fact that I have additional film strength and better resistance to heat. I* figure if I lose a water impeller and the engines overheat someday, the better oil may save me. I also feel better about running them hard, knowing I have the best oil in the sump for the job.
Whoever that mechanic was who said NOT to use synthetic oil, I'm sure he had a reason, but I strongly question his reason for saying so.
regards from Nashville,
Dogsharks (A/K/A "P" )
Having said that, I can tell you that I've been using synthetic oil in my 1984 944 (165,000 miles)for the last 30,000 miles and the car loves it. I run Mobil-1 15W50 summer and go a little lighter in winter.
I've run the same oil in my 1983 928 and it loves it. Presently the 928 is using Amsoil 20W50 and loves that too.
My 1990 S2 is on Mobil-1 15W50.
My Wifes 20-v 5-cyl Volvo turbo is on Mobil-1 15W50.
My twin 427 Ford powered yacht is on Mobil-1 15W50 and those motors love the stuff.
I did some research for the Antique and Classic Boat Society, here in the US, to see if synth oil was compatible with true antiques, some of which have WW-I engines like the Liberty, etc., etc.
On the really old stuff you should use a blend, in order to get the best of both worlds.
On anything from the mid 1960's on up, you should be fine with synthetic. When synthetics first came out, they did have some problems drying out vinyl seals, because they did not have any or enough esters in the formuals, but those years are LONG GONE. Any newer engine such as the 944 will absolutely love the stuff.
Aircraft are not supposed to use a 100% synthetic due to the fact that av gas uses real lead, and synthetic will not act as a solvent for the lead additives, and will create a gum; therefore you will see blends used in aircraft piston engines for that reason.
The main benefits from synthetic oils are better flow when cold, better film strength, less breakdown of viscosity, more resistance to heat, and "no ash" when it burns.
Because of the better flow, if you have an oil leaker now, you know, a car that leaves a puddle on your driveway, then you don't want to switch to synthetic because it will flow out the leak faster than what you're using now. Otherwise there is no harm at all to an engine. Just drain and refill.
Porsche uses Mobil-1 for their initial fill.
I noticed on my 944, that after is sits up for a week or so, it will smoke when I fire it up. I attribute this to the synthetic oil slowly seeping into the valve guides and smoking when I start the car. This goes away immediately, and does not occur on a daily basis when I drive the car, it only happens when I let it sit for a week or more.
As for the marine 427 Ford motors, I like the fact that I have additional film strength and better resistance to heat. I* figure if I lose a water impeller and the engines overheat someday, the better oil may save me. I also feel better about running them hard, knowing I have the best oil in the sump for the job.
Whoever that mechanic was who said NOT to use synthetic oil, I'm sure he had a reason, but I strongly question his reason for saying so.
regards from Nashville,
Dogsharks (A/K/A "P" )
Dogsharks,
Given he runs a veritable fleet of 944 race cars and built the engine for me and has run various engine reconditioning businesses for the last 30+years I do tend to trust his judgement, thats not to say he's right or wrong, but I would certainly take his advice. Especially since he holds the warranty on my engine
>> Edited by dontlift on Monday 10th November 15:27
Given he runs a veritable fleet of 944 race cars and built the engine for me and has run various engine reconditioning businesses for the last 30+years I do tend to trust his judgement, thats not to say he's right or wrong, but I would certainly take his advice. Especially since he holds the warranty on my engine
>> Edited by dontlift on Monday 10th November 15:27
Can you get 15W/50 Mobil 1 over here?? I thought it was 0W/40. I suspect it's expensive and would use more due to the lower viscosity - hence why I've been recommended to use a good quality semi-synth 10W/40. Maybe if you drive flat out everwhere it might make a difference in the long term, but as a road car does it matter so much? 
Thhom said:
dontlift - That's funny, all the people I have talked to (various levels of knowledge) and read of anywhere reckon nothing else than synthetic oil should be used in 944s.
Interesting to read other opinions, though
It certainly is chap, and I shall be probing my man deeply next time I see him.....
Where's Podie when you need him
AJLintern said:
Can you get 15W/50 Mobil 1 over here??
Yip even Halfords sell it, its known as Mobil 1 motorsport this side of the pond.
We've done the engine oil thing many times on here & on gassing- just for the hell of it tho- im not fan of overpriced, overhyped & over marketed Mobil 1, if you want fully synth I'd always go the Castrol RS route, 'tis however IMHO complete over kill on a N/A 944, might as well polish the body with a finely tailored Saviile Row suit rather than a nice clean cloth for all the good it will do you.
Edited to remove the 'e' off the end of suit, coz as far as I know the 3 piece's you get on savile row are the type without the fluffy cushions & reclining backs
>> Edited by iguana on Monday 10th November 19:03
From my experience of running race cars and high performance road cars, here is a possible explanation behind the contradictory advice seen here.
I always use a mineral oil in the race car. Loads of race teams do. A mineral oil will be better when you put it in your engine than an equivalent synthetic oil. The problem with mineral oils is that they break down over time, whereas synthetic oils are more stable. This isn't a problem in a race car, as it is going to be changed a lot more frequently than in a road car. In a road car, you want something that will be stable for 6-20,000 miles, so you use a synthetic.
So, if you want really good oil, and you're going to change it frequently, use a good quality mineral oil. If you want it to last until the next scheduled service, use a good quality synthetic. Whatever you use, go for good quality.
Now for the viscosity. In my TVRs, the factory used to recommend Mobil 1. This used to come as 5W/40 when I first started driving TVRs, but was later changed to 0W/40. A lot of cars used to burn oil, as it was too thin. A lot of cars also used to suffer premature engine wear for the same reason. Now, TVR didn't recommend it because it was great (it isn't, it's actually pretty crap). They used it because they had a deal with Mobil, and they got it cheap.
I used to use Mobil 1 Motorsport in my TVRs (the afforementioned 15W/40). It's thicker, and a lot better for the higher performance engine. As a result, my engine didn't use much oil (although it did use a bit), and it was still ticking along nicely when I sold it with 54,000 miles on it.
I'm no expert here. I am only passing on what I learned from being told by much more experienced racers and engine builders than myself, and from my own experience. I hope it helps.
Cheers
James
I always use a mineral oil in the race car. Loads of race teams do. A mineral oil will be better when you put it in your engine than an equivalent synthetic oil. The problem with mineral oils is that they break down over time, whereas synthetic oils are more stable. This isn't a problem in a race car, as it is going to be changed a lot more frequently than in a road car. In a road car, you want something that will be stable for 6-20,000 miles, so you use a synthetic.
So, if you want really good oil, and you're going to change it frequently, use a good quality mineral oil. If you want it to last until the next scheduled service, use a good quality synthetic. Whatever you use, go for good quality.
Now for the viscosity. In my TVRs, the factory used to recommend Mobil 1. This used to come as 5W/40 when I first started driving TVRs, but was later changed to 0W/40. A lot of cars used to burn oil, as it was too thin. A lot of cars also used to suffer premature engine wear for the same reason. Now, TVR didn't recommend it because it was great (it isn't, it's actually pretty crap). They used it because they had a deal with Mobil, and they got it cheap.
I used to use Mobil 1 Motorsport in my TVRs (the afforementioned 15W/40). It's thicker, and a lot better for the higher performance engine. As a result, my engine didn't use much oil (although it did use a bit), and it was still ticking along nicely when I sold it with 54,000 miles on it.
I'm no expert here. I am only passing on what I learned from being told by much more experienced racers and engine builders than myself, and from my own experience. I hope it helps.
Cheers
James
When I first got my S2 I was running it on Mobil 1, but after it's first service at Hartech , Barry told me not to run it on that, not because it was synthetic but because it was too thin, I was using the 0W40 grade. He said that a good quality semi synthetic was more than adequate for the S2 engine, after all it's hardly over stressed at 70bhp/litre. Since that day I've run it on Castrol GTX Magnatec 10W40 and I 've had no problems, and I've saved a load of money!, also hot oil pressure is up bu about 0.5bar.
I've heard from people on Rennlist that you can encounter problems when switching from synthetic to mineral, something to do with the seal reacting to the oil and shrinking causing lots of leaks, but don't quote me on this!
I used to run an Audi S2 Quattro and I still browse the forums for that car and somebody mentioned the other day that they had been quoted £250+VAT for a 205 litre drum of Castrol RS 10W60, he was going to confirm that as it sounded too good to be true, I'll let you know of the outcome.
Andy
P.S. I run the Redline 75/90NS oil in my transaxle and it's really good, VERY expensive though, I'm going to try Swepco at the next change.
I've heard from people on Rennlist that you can encounter problems when switching from synthetic to mineral, something to do with the seal reacting to the oil and shrinking causing lots of leaks, but don't quote me on this!
I used to run an Audi S2 Quattro and I still browse the forums for that car and somebody mentioned the other day that they had been quoted £250+VAT for a 205 litre drum of Castrol RS 10W60, he was going to confirm that as it sounded too good to be true, I'll let you know of the outcome.
Andy
P.S. I run the Redline 75/90NS oil in my transaxle and it's really good, VERY expensive though, I'm going to try Swepco at the next change.
Gents,
Please remember my comment about people who think they know it all.....and please understand I'm not preaching here, I'm just trying to share what I know.
The chap who is getting advice from a guy who runs a fleet of 944 race cars, or whatever, is getting suspect information, in my humble opinion. If mineral is so good, how come Porsche themselves uses it for their initial fill?
Also, if mineral is so good, how come the synthetic film strength is better, resistance to heat is better, and flow is better. Tell me what is better with mineral oil, remembering you pump the stuff out of the ground and synthetic is a totally engineered product.
If anyone is interested in wear, take another look at the Amsoil motor oil page I referenced, go ahead, look at it, it won't hurt ya. Amsoil is tested waaaay better than any mineral oil I know of, period. As far as I'm concerned, it's a battle of the synthetics, and mineral oil isn't even in the game. It runs cooler, with far less friction, gives every advantage and only has the drawback of cost.
As for the yacht, yes, it's a 1966 38-foot Chris Craft fiberglass Commander, with original 427 power. When the big dogs bark, everyone generally takes note. When I run those at 3000 rpm, I'm pushing nearly 20,000 pounds at nearly 30-mph. At 4,000 rpm I'm getting into 32 to 34-mph range, and that is fast for a boat that size. There is a tremendous amount of stress when running 900-footpounds of (combined) torque through 2.5:1 gear reduction transmissions, and swinging 24" props. That's why I use a synthetic oil, to be sure I have the best film strength and heat resistance, etc., as an extra measure of safety.
The same goes for the Porsche wasserpumpers. As an added byproduct, some of the synthetics will produce "no ash" when burned, and some of the cough, cough, stinkey mineral oil will leave a lot of residue and this can cause deposits on the valves and it can blow by into the sump eventually and contaminate the oil over time but most of this may just be visual. My engines all appear to run very clean internally, with NO sludge, not even a hint of it.
It's your vehicle, your money, and your choice !
regards, P
Please remember my comment about people who think they know it all.....and please understand I'm not preaching here, I'm just trying to share what I know.
The chap who is getting advice from a guy who runs a fleet of 944 race cars, or whatever, is getting suspect information, in my humble opinion. If mineral is so good, how come Porsche themselves uses it for their initial fill?
Also, if mineral is so good, how come the synthetic film strength is better, resistance to heat is better, and flow is better. Tell me what is better with mineral oil, remembering you pump the stuff out of the ground and synthetic is a totally engineered product.
If anyone is interested in wear, take another look at the Amsoil motor oil page I referenced, go ahead, look at it, it won't hurt ya. Amsoil is tested waaaay better than any mineral oil I know of, period. As far as I'm concerned, it's a battle of the synthetics, and mineral oil isn't even in the game. It runs cooler, with far less friction, gives every advantage and only has the drawback of cost.
As for the yacht, yes, it's a 1966 38-foot Chris Craft fiberglass Commander, with original 427 power. When the big dogs bark, everyone generally takes note. When I run those at 3000 rpm, I'm pushing nearly 20,000 pounds at nearly 30-mph. At 4,000 rpm I'm getting into 32 to 34-mph range, and that is fast for a boat that size. There is a tremendous amount of stress when running 900-footpounds of (combined) torque through 2.5:1 gear reduction transmissions, and swinging 24" props. That's why I use a synthetic oil, to be sure I have the best film strength and heat resistance, etc., as an extra measure of safety.
The same goes for the Porsche wasserpumpers. As an added byproduct, some of the synthetics will produce "no ash" when burned, and some of the cough, cough, stinkey mineral oil will leave a lot of residue and this can cause deposits on the valves and it can blow by into the sump eventually and contaminate the oil over time but most of this may just be visual. My engines all appear to run very clean internally, with NO sludge, not even a hint of it.
It's your vehicle, your money, and your choice !
regards, P
AJLintern said:
Can you get 15W/50 Mobil 1 over here??
You can get the 15w/50 from www.Teesideautotech.co.uk they do 4 x 4litre containers for £110 with free delivery. Not listed on their website but call 01642 617626 for the up to date price
>> Edited by diver944 on Tuesday 11th November 01:14
here's something for you guys to look over. This is a great source of info, albeit a bit dated, but look at the flow, heat resistance, etc., for Mobil-1 and Amsoil, compared to the non synthetic oils, and you'll see what I'm talking about. Also see the "no ash" comments, and general endorsements of synthetic oils.
www.vtr.org/maintain/oil-overview.html
regards, Dogsharks, Nashville, TN, USA
Hey guys, it's 7:30 pm over here, what's it doin in UK??
www.vtr.org/maintain/oil-overview.html
regards, Dogsharks, Nashville, TN, USA
Hey guys, it's 7:30 pm over here, what's it doin in UK??
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