im gonna use what icemark uses...

 

same here... im in san diego, will 20w50 castrol gtx work fine? i dont really race and rarely do i take it over 5-6 thousand rpms. the cars for college, well at least for now...

 

Castrol GTX is 3.20 here Royal Purple is 5.60. And it costs me right around 20$ in gas to drive to the nearest store that sells oil :-P I run RP

 

I use generic 20W50 in the warm weather, generic 10W30 in the cooler weather. Whatever is cheapest at the store when I buy it.

Also, I feel compelled to mention that there are about 10,000 oil threads already out there. A search for "oil recommendations" or similar should turn it all up.

 

yeah... but with that many threads on what oil to use, you get more confused. i think thats why people keep bringing it up. they just want a straight foward answer.

 

good luck, cause there is no straight answer. bottom line is, it doesnt really matter. as long as you use a fairly good quality oil and change it when it needs it, you'll be fine. if you really rag on the car, then it becomes more important, but when you get down to it its application specific, depending on mods, temperature, redline, etc.


and icemark id rather have it be a little thin and coat everything real good when i start then have it be nice and thick and all stay in the oil pan. thin when starting is good IMO, ti gets everything nice and lubricated real quick. startup is arguably where the most wear happens due to the fact that everything is not fully lubricated.

pat

 

or the oil all runs to the pan, as soon as the engine is cold/cools down...

So you have to pump twice as much oil to lubricate when cold, whereas the proper weight would already be stuck to the surfaces providing the much needed surface film against wear.

 

considering how long it takes the block to cool, that doesnt make much difference, since if it gets cool, chances are its parked long enough for the heavier weight oil to drain off too.

the oil pump only has a certain capacity. if it has to pump thicker oil, it will pump less, so if the oil is really thin, you will have more volume no matter what. and it isnt so much sticking to the surface, as any fluid will do that, its flowing enough to coat the surface, so the more volume the better, and thinner will make its way into seals and crevices quicker, so less wear. i mean thats the whole point behind multi weight oils. having a larger split is just more advantageous and made possible by newer technology.

pat

 

Ah, yeah... okay...

Try this then, go get two new needle nose pliers, put a drop of 20W50 between the jaws on one, and a drop of your 5W50 between the jaws of the other (for this test to work you must use the same amount of oil on each one) and then close the jaws.

Then suspend the pliers over a piece of white paper (needle nose down) overnight.

Tell me which one has a bigger spot in the morning.

I know... you might say "pliers are not motors", but the tolerances of the new jaws (old used ones won't work-they are already worn) are actually much tighter than most of the clearances of our engines, and will give you a great test on film cling at cold temps.

 

hey mark im a poor college student, i cant afford **** like that. i get your point, i just dont think that even 20w is enough viscosity to cling to an engine overnight. i mean... picture a side iron, do you think that thing is still gonna have a thick enough film after 8 hours to do any good?

anyway, if 5w is too thin, how do all these newer motors in the econo cars last so damn long? i know they have to run the thinner oil due to tighter tolerances, but the point should still be valid.

pat

 

damn..i wish my digicam worked. heres what im gonna do. im gonna take a intermediate iron ( dont ask me why i have one at my tiny *** apartment), and smear one side with some spare 5/50, and the other side with 20/50. i'll even buy castrol 20/50 to make it fair, then i'll check it every time i come home from class for say 24 hours. and we'll see how long it takes each to run off enough to prevent proper sealing and lubrication.

after im done with that, i'll take a capful of each, and pour it on something (got any suggestions) and see how long it takes each to spread and penetrate far enough to lubricate.

then we can compare.

i'll go to the store and get some oil tomorrow

pat

 

just a question i own a 88 turbo vert and my turbo is internally leaking oil and blows blue smoke out the exhaust the engine is freshly rebuilt street port with 5200kms just broken in iv been running castrol gtx 10-30.. but if i run 20-50 will it somewhat help the turbo leak and minimize the blue smoke? untill i can rebuild the turbo?

 

not really. maybe just a tiny bit.

just rebuild the critter, it snot that expensive

but hey, when you rebuild it, try not to break the turbine shaft. cause thats what i did to my t4 today, and now im fucked.

not that you would break it, im just whining

pat

 

Has anyone used mobil 1 15w-50 performance formula synthetic? I got some and am putting it in this weekend. Just thought I would try and get some feedback before I do it. I'm using valvoline 20w50 synthetic right now, and all I can say is at high rev with no load its alot smoother, plus it starts alot faster. Maybe Mobil 1 synthetic will provide more of a gain. BTW, I've disabled the OMP and run valvoline 2 stroke at 100:1

 

valvoline synthtic motor oils are one of the problem ones and should be avoided in a rotary motor as it is very high in ash content (ash as in what is left after it is burned).

 

No, you have a bad seal.. running a thicker oil won't band aid it much

 

Newer cars use newer materials/alloys that were not able to be used for our engines. (heck you can see this just by look at the new 2 piece apex seals Mazda is using now for the reni over what came with our cars- good enough that they even replaced the apex seal for our motors with it).

The engine build tollerances are also much better.

And most manufactures were getting 100-120K mile life out of their engines with the old materials, with the newer ones it is not unheard of getting 200K mile or more life- twice what the manufacture designed for so they are willing to compromise on engine wear to get a little better mileage and cut the engine life back down a little.

And finally, oil companies are forced to produce better quality product (than 20 years ago- when our cars were first built), resulting in engine enginners able to spec tighter tollerances for better sealing and performance and lower emissions.

That is why you see many newer cars spec'ng thinner oils.

Remember everything on cars is a compromise. Trading off more power for less reliability is a common aftermarket one. Trading off engine life for gas mileage and emissions is a current one used by many manufactures, after all how much money are they making off you if they build a car that you keep for 20 years- heck even 10 years- ideally they want you replacing your car every 5 years.

 

i dont think thats how it works. in most newer cars spec'd for 5/30, running a thincker oil will cause improper lubrication to the valvetrain, because the pumps and oil passages are designed for thinner stuff on purpose.
if you take one of these motors apart, even after 100-200k miles, they are remarkable nice inside. i have several late 80s-early 90s cars that have over 200k miles on them, and still run fine, but had to be parked because the rest of the car fell apart.
it is true that oils are better, and that plays a big part in this, but thats what im arguing anyway, is that the newer oils with a big viscosity split are superior to 20/50 racing thats been around forever.

 

Thanks for the heads up on Valvoline Mark. I'm goin down to change to mobil 1 right now, I'll post back in a bit and tell ya'll how I like it.

 

The mobil 1 15w-50 I just put in made no difference. Switching back to good ol Castrol GTX 20w50 next change. Or maybe a synthetic blend, judging from how clean the valvoline 20w-50 synthetic I just took out was.

 

The Vavoline Synthetics have an ash percentage of up to 1.5 %... about double what most conventional oils have.

Mobile 1 is a good choice for engine oil (I use it in my Lexus and Toyota Truck), but like Ted, I think that a synthetic oil in a rotary engine is a radical waste of money.

 

Thats crazy to think it's got that high of a percentage but came out at 3500 miles so clean. When I was using Castrol GTX it would come out pitch black. The valvoline came out only mildly darker than it went in.

 

Ash percentage is whats left after it is burned... you'd be more concerned with the sludge build up in the motor (even more so with the MOP still working).

The color of the oil that comes out at changes relates more to how well your engine seals.

*edit< Also the anti oxident level in the oil (typically Zinc dithiophosphates, hindered phenols, aromatic amines, sulfurized phenols) can driectly contribute to the color.

 

OHHHHHH, it makes a lot more sense now. thanks again.

 

does it matter if i mix oil's? Ive got about 2/3's left. ANd im nowhere near my oilchange. when it gets about 1/3 left i want to put more oil in. Should i just do a oilchange even if im not near the time/milage?