What engine oil do you use?

[NSEX]

I've been using Mobil 1 for years, but I used Castrol for my last oil change and now I heard Castrol isn't good because it's not as synthetic as it used to be.
On the other hand, a S2000 driver told me that he feels his car is quicker using Castrol than using Mobil 1. I'm confused.

 

[Number9]

The Castrol "synthetic" uses a dyno base and sythetic additives. So if you're a synthetic purist, Mobil 1 is the better choice.

I'd be more concerned about viscosity range and frequency of change. I use redline synthetic only because that's what my respective NSX and Dinan shops happen to carry...

--twc

 

[286 NSX]

i stay away from synthetic because local shops say it wears down your rings a lot faster. only use it if you need it, like in turbo cars, supercharged, where the temp is high. rotaries aren't allowed to even use synthetic. mazda doesn't warrenty it. same issue, it wears down the apex seals. and this is a fact.

 

[Number9]

It doesn't wear rings faster. I think you might be confusing this with earlier phenomenon when first gen synthetics appeared to cause various seal leaks because the synth oil didn't have the same properties as dyno oils with respect to the seals and the seals shrunk and then leaked. Current gen synth oils don't have this problem and can be mixed with dyno oil too. Synthetics of the right viscosity range flow better when cold and withstand heat better. No downside, except for price...

--twc

 

[nsxman]

FWIW.

Mercedes recently issued a notice to its dealers recommending that all 98+ vehicles use synthetic motor oil exclusively.

 

[Andrie Hartanto]

Originally posted by nsxman:
FWIW.

Mercedes recently issued a notice to its dealers recommending that all 98+ vehicles use synthetic motor oil exclusively.

Yep, Porsche been doing it for a while. BMW started recently as well.

 

[286 NSX]

thanks for the info guys. but the synthtic issue on the rotaries is true. and one more thing, is it true once you go with synthetic, you can't go back?

 

[nsxman]

"is it true once you go with synthetic, you can't go back?"

No.

 

[David]

Originally posted by 286 NSX:
i stay away from synthetic because local shops say it wears down your rings a lot faster. only use it if you need it, like in turbo cars, supercharged, where the temp is high. rotaries aren't allowed to even use synthetic. mazda doesn't warrenty it. same issue, it wears down the apex seals. and this is a fact.

That is actually not correct. Synthetics are significantly better lubricants than standard oils. Nothing will wear more with a synthetic. They are also significantly better at high temperatures than regualr oils, which will break down under exterme temperatures. In fact, the only applications where synthetics are not as good are those where the mechanical design relies on a certain minimum level of friction to function. For example, putting a synthetic trans oil (Redline, for ex.) in an old syncromesh transmission (old Alfa, for ex.) may cause it not to work properly because the syncros need a bit of friction to function.

There used to be a sort of 'folk lore' among mechanics that you should use regular oil to break in a motor, becuase synthetics are so slick the motor will not break in properly if you use one right from the start. This is obviously not true, and every major auto manufacturer will agree if you call and talk to a tech advisor.

The issue with Mazda rotaries is not a problem with the apex seals. It is really due to the type of oil pickup that Mazda uses in the rotary engine. Their engineers do not feel the pickup will work as well with a synthetic; hence the warning. I had a detailed discussion about this issue with a Mazda factory engineer when I was racing first gen RX-7s back in the days of dinosaurs (they won the SCCA GTU class for almost a decade straight, by the way). After consulting with them, I ran Redline in all of my rotary race motors with no problem.

I personally believe that Redline is the best synthetic, but I use Syntec in my cars because I think it is nearly as good and is more readily available. In most of the independent magazine tests of synthetic oils, Mobil One consistantly does very poorly. Even so, it is the most popular synthetic. Go figure.

Sorry to blab on so long about such a simple subject, but it is something I researched pretty heavily back when I was roadracing seriously.

[This message has been edited by David (edited 13 February 2001).]

 

[nsxtasy]

In most of the independent magazine tests of synthetic oils, Mobil One consistantly does very poorly.

Not true.

 

[David]

I did some more looking around and it appears Mobil 1 did a significant reformulation in 1995, which is right after I stopped paying attention to synthetic research. Here is an interesting article on the various types of oil and the relative characteristics of each.
http://www.geocities.com/MotorCity/Downs/3837/oilprime.html

[This message has been edited by David (edited 13 February 2001).]

 

[NSEX]

What's the difference between Mobil 1 5w/30 and 10w/30?

 

[PUREVIL]

I use Moblie 1 synthetic only.

A Honda mechanic told me that Pennzoil makes the heads all gummy and recommended not using it.

 

[David]

Originally posted by NSEX:
What's the difference between Mobil 1 5w/30 and 10w/30?

To decode viscosity ratings, etc, refer to the article I link to above. It is a pretty good basic overview.

 

[Chris W]

While we're on the subject of oil types, have any of you guys used other brands of oil filters besides the Honda brand without incident or is this a NO NO?

 

[DocL]

Originally posted by Chris W:
While we're on the subject of oil types, have any of you guys used other brands of oil filters besides the Honda brand without incident or is this a NO NO?

I just switched over to Mobil 1 5W/30 this weekend and I only use the Honda/Acura oil filter. If you've ever dissected an oil filter, you'll see why Honda's oil filter is better than other brands. Also, It's a cheap part considering the risk you would be taking by using an aftermarket cheapo filter.

 

[nsxtasy]

I use strictly 10W30 because that's what the factory recommends.

Pure synthetic, major brands (Pennzoil Performax or Mobil 1).

 

[NSX4U2]

Mobil 1 10W30 only! Am I missing something?

 

[Andrie Hartanto]

Redline 10/30

A friend in E30 M3 race cars running redline loss his oil pressure (idiot lights came on) 4 laps before he finished. He opted to run the car until the engine blows. He finished the race in race pace, and the engine quit in cool down lap. Talked to few people and everybody said they don't know any car that would last 4 laps in race condition without oil pressure in any kind of oil.

I've been using redline since. I'm a believer.

 

[BladesNSX]

I remember an acura tech. telling me that Honda recommends only motor oil and not synthetic. I dont remember the details of why. However my question is: if you don't really race your NSX. What is the benefit of using synthetic over motor oil?

 

[nsxtasy]

if you don't really race your NSX. What is the benefit of using synthetic over motor oil?

It flows better in very cold temperatures and it's more resistant to breakdown at high temperatures.

 

[NSXY]

I don't know about you guys, but my NSX came equipped with a thermostat that regulates the temperature and flow of PEG-containing water out of my radiator and into my engine. With this device installed, the water that circulates through the engine's core keeps the engine at virtually the same operating temperature no matter where and when I drive. What don't I get here? Is there something not right with using Acura's (Honda's) recommended 10W30 oil if I have a termostat?

------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Stock, except Dunlaptya SP9000s

[This message has been edited by NSXY (edited 21 February 2001).]

 

[nsxtasy]

With this device installed, the water that circulates through the engine's core keeps the engine at virtually the same operating temperature no matter where and when I drive. What don't I get here? Is there something not right with using Acura's (Honda's) recommended 10W30 oil if I have a termostat?

Well, for one thing, I bet it's not at that operating temperature after the car has been sitting (power off) overnight...

That being said, if you're changing the oil reasonably frequently (every 3-4K miles or 3-4 months), you're probably fine if you use conventional 10W30. As for myself, I'd rather spend a few bucks extra to protect my $20K engine with synthetic 10W30. YMMV.

[This message has been edited by nsxtasy (edited 21 February 2001).]

 

[scott]

I run mobile 1 and am happy with performance. It has less friction for a given viscocity. When it is cold it will start easier when using synthetic and engine has more juice due to lower friction.

As far as heavy duty test, I blew an oil return line on my turbo (Porsche) drained all oil. I still drove it for 2mi no problem. I am sure another oil would have siezed the engine.

I have heard the same on Penzoil and slick 50. They gum up on joints when added post rebuild.

 

[BladesNSX]

OK I am sold. So which Synthetic should I use? Testimonials please: