Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

[GaryR]

I'm with Steve, if you value the engine in your car (regardless of make) then use the best oil you can and change it accordingly. In our new BMW I use M1 and change it at 5K, same thing for my road Porsches. I consider oil changes cheap insurance..

[teenerted1]

oil change this weekend after a 2700+ mile road trip and one more tank of gas to get to 3k
20/50 brad penn...first time ever there were no fine metal shavings on both the drain plug magnets!!!!!
now this oil was only in the 911 for maybe 3 weeks.

the oil change before the trip was also after a long road trip 2500k+ but with more flucuations in speed/driving conditions. that trip involved a track day in the middle.
and the oil change before the first road trip of the year was after a winter full of driving.

the level of sludge and fine shavings went down with each change this year.

this does tell me that long sustained constant freeway speed is much easier on your engine. so the whole idea of changing every 3k/3months is starting to make sence.
looking forward to seeing my oil conditions after another normal summer of driving. no more big trips planned, just the usual weekly drives and an occassional long weekend overniter.

the old 911 has done over 6000miles this year already and has never run better.

[brads911sc]

I agree.

The interesting thing is that the sticker the dealer sticks in your car still says 3k miles.

The other thing they did is reprint manuals saying regular fuel is fine with an *. The * states, for optimal performance use premium fuel. What? Why would I want anything less than optimal performance? Yet the fuel door still says "Premium Fuel Only"...

They have been using this 2.0T which required 5k oil changes and premium fuel for how long? Its a spin off of the 1.8T which i owned in a 2000 Jetta and that had the same 5k intervals and fuel requirements.... they havent changed a thing in years yet the intervals change.

The other interesting thing is that they use the same engine in the Audi A4 and TT and there is no mention of using regular fuel and longer oil change intervals over at Audi.

Hmmmm Seems like marketing... and the sad part of all of it.. is that they are now calling the shots at Porsche....

I would use the best oil your comfortable with... and keep the intervals short... youve convinced me. Put some M1 in that focus.

Originally Posted by Steve@Rennsport

Totally concur,....

The main reason for oil changes is to flush the byproducts of combustion from the engine and leaving the oil in the engine for 10K, 15K, or 20K runs counterintuitive to that principle, regardless of what type of oil is in use.

OEM's are trying to sell low costs of operation as a major marketing tool and thats one main reason they often recommend those long drain intervals. Porsche, as well as VAG has been forced to revise some of their (absurd) extended drain intervals for several reasons including wear and sludging in some engines.

From my perspective, changing the oil more frequently (using a good product) pays big dividends over the long term and for people who keep their cars for a long time, its something to think very carefully about.

Remember, the OEM's do NOT have your best financial interests at heart: their job is to sell cars and parts as thats the only way they make money and stay in business.

[longhornchris04]

Brad-

The reason modern cars can handle regular fuel is that the ignition system on most new cars (certainly any that 'requre' premium) has automatic knock detection. Thus, if you put in the cheap stuff and the engine starts to knock it will automatically retard the timing. I think newer turbos may also lower the boost to help as well.

The end result is lower power, but the engine won't self-destruct. Its still not really good for the engine, as its now having to operate off-design, but it won't destroy it. The good news is that, in a pinch, you can put a tank of regular without risking the engine in a more modern car. On older vehicles, this was not the case.

Now, the opposite is not true... i.e. if the engine (such as my Focus) doesn't have a high compression engine, then there is no benefit to using high octane as the timing was setup for regular to begin with.

[brads911sc]

Thanks for the education and information. Sorry to get off topic with my posting.

Originally Posted by longhornchris04

Brad-

The reason modern cars can handle regular fuel is that the ignition system on most new cars (certainly any that 'requre' premium) has automatic knock detection. Thus, if you put in the cheap stuff and the engine starts to knock it will automatically retard the timing. I think newer turbos may also lower the boost to help as well.

The end result is lower power, but the engine won't self-destruct. Its still not really good for the engine, as its now having to operate off-design, but it won't destroy it. The good news is that, in a pinch, you can put a tank of regular without risking the engine in a more modern car. On older vehicles, this was not the case.

Now, the opposite is not true... i.e. if the engine (such as my Focus) doesn't have a high compression engine, then there is no benefit to using high octane as the timing was setup for regular to begin with.

[dsmithwc04]

Well, I use the Synthetic Mobil 1 becuase it really isn't that expenive with $23 for 5 quarts. Cheap insurance and I feel good about 7k miles intervals. Same cost as conventional if allowing the slightly longer drain interval but a better oil from my research on the net. My wife's Jeep Liberty CRD ( 2.8L Turbo Diesel ) loves Mobil 1 Turbo Diesel synthetic oil with a 7k mile interval as well. It would be interesting to send in some samples to blackstone and see what they think...

[Navaros911]

This is one big thread... I've been reading up on this topic for days now and I still don't know what direction I should go.

I need to do an oil change in a month or so.

Anybody have experience with V300 5w-40 in high temp environments (the current 0w-40 M1 -API SL - that hurts the engine) doesn't cut it. Is the V300 better?

Short listed for possible order I have (no particular order):

1/ Bradd Penn Grade 1 20w-50 (pro: it sounds like this is the best stuff out there for air-cooled 911 engines; con: I need to have it shipped, 20w sounds a little thick)

2/ Motul 300v 5w-40 (pro: I can get it shipped as part of an order of parts, looks like a very good oil on paper; con: expensive, not the best temp range I think - current 0w-40 runs a little hot)

3/ Castrol TWS 10w-60 (pro: it is a good API, good temp range, used by BMW on their high end M-engines, easy to come by; Con: need to have it shipped increasing the price to V300 level)

4/ Mobil 1 15w-50 (pro: available here, but need to check the API, good temp range for this climate; con: it costs as much as the v300 and castrol)

I'm tempted to try V300 and stock up on the Brad Penn or Castrol.

[dmwallace]

Here are a few suggestions that have been discussed in this thread:

1. SWEPCO 306 has a 15w-40 and is one of the "short list" oils that HarryD has on page 1 of the thread. I believe they distribute across much of the world so perhaps it might be available to you since they market to diesel truck fleets.

2. Brad Penn has a 15w-40 now available (not in their product line when this thread was begun). Also, Mr. Navarro previously posted in this thread that it would be fine to mix equal amounts of the BP 10w-30 & 20w-50 to get to a 15w-40. This might also work for you if you can't find the 15w-40.

[DPDISXR4Ti]

Originally Posted by Navaros911

This is one big thread... I've been reading up on this topic for days now and I still don't know what direction I should go.

Which engine?

[ToddM]

Originally Posted by dmwallace

Here are a few suggestions that have been discussed in this thread:

1. SWEPCO 306 has a 15w-40 and is one of the "short list" oils that HarryD has on page 1 of the thread. I believe they distribute across much of the world so perhaps it might be available to you since they market to diesel truck fleets.

2. Brad Penn has a 15w-40 now available (not in their product line when this thread was begun). Also, Mr. Navarro previously posted in this thread that it would be fine to mix equal amounts of the BP 10w-30 & 20w-50 to get to a 15w-40. This might also work for you if you can't find the 15w-40.

Not only do they now have a 15W-40W, BP now also distributes a 10W-40. We were all mixing 10W-30 with the 20W-50, but now you can just get what you need direclty by the quart.

[Navaros911]

Thanks for the tips guys, but I need something that is a little thicker at high temp. I get an oil pressure warning when the engine gets hot sitting in traffic.

All stuff is working fine (thermostat, blower, ...), but these cars were not made for 50 degrees Centigrade... so as the temp rises to 3/4 of the range the oil pressure warning goes on. Getting her rolling and some good airflow brings it down to 1/2 again. So I was thinking of a Xw-50 or 60.

What about the motul... sounds like not many out there with experience.

This is for the 964 engine... completely stock with 75k miles.

[Steve@Rennsport]

Originally Posted by Navaros911

Thanks for the tips guys, but I need something that is a little thicker at high temp. I get an oil pressure warning when the engine gets hot sitting in traffic.
What about the motul... sounds like not many out there with experience.

JMHO, but you need a 15w-50, 20w-50, 20w-60, for safe operation at those outside air temps.

I've plenty of experience with Motul 300V and I'd recommend it very highly. Provided one has the budget, there is nothing better.

[RWebb]

I wonder about your oil pump....

[cnavarro]

Yup, above 90F ambient, go with 15w50 or 20w50 in an aircooled car. We're even seeing the water cooled cars needing thicker oils at those temps on the track. We've seen oil temps on a Boxster upwards of 270F after a DE session.

[SRT356/911]

I think Swepco is the best bet. They will ship your first case free.

From then on it is free shipping if the total is over $500.

We banded together and I order Swepco for several people and it is delivered to my door free.

I do not trust Mobil to not make anymore changes that will cause damage to an engine.

[oreke]

Hello,

I read through many pages of this post and others. I may have missed the answer to this, but are the conclusions about ZDDP levels also valid for the water cooled, roller-tappet engines, like the 944 series? Do those models also need the high ZDDP content oils that the flat-tappet engines do? If not, is there are disadvantage to using something like Brad Penn with high levels of ZDDP (catalytic converter wear)?

Thanks,
oreke

[RWebb]

1. no
2. no

[mikesride]

pennzoil gt 25/50 for off road use only has always been my track oil of choice.

[nize]

Originally Posted by oreke

Hello,

I read through many pages of this post and others. I may have missed the answer to this, but are the conclusions about ZDDP levels also valid for the water cooled, roller-tappet engines, like the 944 series? Do those models also need the high ZDDP content oils that the flat-tappet engines do? If not, is there are disadvantage to using something like Brad Penn with high levels of ZDDP (catalytic converter wear)?

Thanks,
oreke

not sure where you are getting false information but the 944 does not have roller-tappets.

the 944 has flat tappets.

[saurkraut]

I wonder if there is any ZDDP in this stuff

AeroShell Multigrade W 15 W 50 - Shell Aviation