In general. It's crazy what they're doing to oils. Oils with the GF4/SM specifications are not what I would want in any engine of mine. Many governments and auto manufacturers will differ with me in that statement but we know what we want and we know what we're looking for.

Paul.

 

i used to believe in synthetic(and they do have some advantages) but when i tore down my 50K engine(in which I ran a very popular 5/30 and 10/40 brand) my eccentric shaft front bearing on the bottom side, not top--was almost worn through the copper. Other bearings looked ok--so you may think it is a load thing. I dont know what would place a load on the bottom part of the bearing. So now i run a 20w 50 dino oil.
just my decision.
olddragger

 

now u make me think that I should start using at least 5w40 like right away ! -_-

meh ... maybe I should

 

double,

makes me say hummmm...

thanks for the work..

beers

 

Some more information about this?

 

20w50, that's like some carbonic syrup. you should probably run a pre-oiler to help get that through the engine on start up, or it may just stick to all the stuff from the last run....

 

Don't let the modern marketers fool you into thinking a 20W won't flow well at start-up. They were perfectly fine in the past and nothing has changed matrial-wise or clearance-wise. Is it ideal?

Seal.

 

Funny.

Do you have any idea what you're talking about ?

 

i also live in a warm climate
OD

 

unless its a 150 def F outside, its not warm enough to matter...

 

it wasn't intended to have much educational value to it....

just saying "wow, that's thick"....


20W50 is what the old rotaries used right? obviously the advantage is that it's thicker so it should reduce wear, but it is getting on the thick side.... there have to be some disadvantages, right?

 

I see what you're trying to say, but the "truth" is not what you're thinking.

 

We should all be saying, regarding 5W20, WOW THAT'S THIN! Unfortunately the training toward the opposing view is very effective.

Paul.

 

20W50 is the stereotypical race weight... oils are good for track days, not designed 1 iota for cold start, extended idling or long term oil longevity

 

my 7 only tachs out to 8000 and I wouldn't put less than 20W-50 in it.

 

it was 140f degrees on the pavement at Road Atlanta this past summer

OD

 

I would second olddragger on temps. It all depends on where you measure it.

I have walked outside in the summer after work and had the 8's temp gauge pointing straight up before starting. Between the heat from the morning commute remaining in the engine, and ambient being about 120, the oil may still be at operating temps 9 hours later.

The surface of the asphalt will be a lot hotter than the 120 ambient. I started using synthetics because of the heat here.

Does 5-20 makes sense? I don't think so. I am open to ideas as to what viscosites are correct. Heavier is starting to look good for Arizona.

 

go ahead and trade minimal protection increases at high revs for a 10 fold decrease at cold starts... not my engine -shrug-

 

I dont see a problem with the oil pump pumping 10 even 15 weight oil at startup.

 

waiting on your thoughts on this matter ^_^

 

Then maybe you should explain the wear on olddagger & expo's motor.

 

what's the best weight oil to use then on a daily driven 8?

 

10w 40 recomendation comes from a trusted source.

5w 20 is what the manual calls for and is likely a partial culprit for the early demise of some hot weather engines. I'm using 10w 40. As an aside, I didn't buy my RX8 for the gas mileage... but I did manage 22 mpg from the last three tanks using 10w 40. So, the insainly light 5w 20 Mazda recomends isn't really making any dent in the mpg department.

... now please go back and read some more of this thread!

 

I haven't had any problems with 5w30 Castrol GTX (0w30 Castrol Syntec for the synthetic folks) and would easily recommend it to other 8 owners and also any piston engine that can run oil of this weight

 

Yeah same here I run 5w30 Castrol dino oil.

Would I really benefit that much of moving up to 10w40?

I really dont stomp on my car all day when driving it. I am in Dallas, TX tho.