DamonB

I posted some great info I came across here.

rotary-tt

Finally someone who agrees that thinner is better! (for street use). Oil flow rate is important, exp. in a rotary where the oil is used to carry away heat to the oil cooler. Thicker oil will elevate temps in critical areas since the hot, thicker oil will remain in the same place for a longer time (thicker will reduce flow rates).

I stick to the recommended 10w-30 in the warmer months and use 5w-30 in the winter. Either Mobil1 or Royal Purple

gago

I switched to mobil one synthetic about 2 weeks ago. 15w 50

Now I have small puddles on the ground. First I thought it was the oil pan. I had to tighten whatever I could get at. Took it to work and back and still had a leak. It looks like it is coming from the front of the engine. around the metering oil pump (passenger side). any ideas??????

mileage on the reman motor is 19k

gago

??

SPOautos

Its cause syn is very slipery and designed to get into cracks where regular oil cant get. This is how is slips thru the engine and ends up on your garage floor.

If your going to run syn you need a very tightly sealed engine or you'll spring leaks everywhere.

STEPHEN

Boostedtwice

The syn oil cleans out any goop or grim out of cracks within the engine my mech. told me only to switch if the motor is under 20k or else it will clean out the grim a spring leaks but that was when i had a piston engine

nickpapagiorgio

This may be redundant, and correct me if I am wrong but if you use a conventional oil with a synthetic premix, wouldn't that be the best of both worlds??

gago

the motor is under 20k

I will switch back to dino and see what happens...

tmiked

Interesting,many knowledgeable people would say use a synthetic oil and a conventional premix !

Synthetic is best by far in the sump because it lubricates better, doesnt break down at high temperatures and stays on the parts requiring lubrication better when the engine is stopped. Remember the Ad. "90% of engine wear occurs at startup" This is the big advantage of syn oil in any engine. A pre-mix of synthetic two-stroke is proabably slightly better tha conventional oil.
Synthetic oil doesnt thicken as much at low temperature just as it doesnt thin out as much at high temps. Hence, the 'leakage increases' while the engine is sitting from using syn oil. The cleaning effect may be a factor also.

Blake

Pineapple Racing has always recommended the use of synthetics, particularly Mobil 1. As most of you know, Rob stands behind his work to the tune of 5 years, which says something for his conviction. The fact that he is still in business, having offered such a warrantee for so many years (over 20), says something about his knowledge and craftsmanship. He also runs Mobil 1 in his own vehicles. In fact, he only changes the filter every 3,000 miles; the oil gets changed once or twice a year. Perhaps he's brave. Or perhaps he knows someone that can rebuild his engine cheap. I dunno, but it works for him -- and has for MANY years. He has seen no correlation between using any quality synthetic, in a motor that retains the stock OPM, and the feared excessive carbon buildup rumored to happen ostensibly "because synthetic oil doesn't burn". In fact it's less. Whatever theories people have about how synthetic oil does or does not burn can be discounted out of hand because there is -- and has been for a very long time -- a great deal of actual evidence to prove it one way or another. In other words, when theory and experience do not agree, you discard the theory.

I, personally, use Royal Purple. It helps that I have a sponsorship, so they just ship me 5 gallon containers of Racing 21 and cases of gear lube, premix, and bearing grease. Obviously, I'm a bit biased toward their products. On the other hand, I bought their products retail before the sponsorship deal and that is what sold me on them -- that, plus the fact that one of their main engineers (David Canitz) is an RX-7 owner! Great guy, too.

So, should you switch to synthetics? Not necessarily. Older engines don't get all the benefits (already worn) and synthetic oil tends to leak around the oil control seals in older cars. There is nothing really wrong with mineral oil, so s]don't despair. But, fresher engines shortly after break-in are prime candidates for the upgrade. Should you do what Rob does and only change the filter every three months between 1 year oil changes? On NAs, yes, he says that is acceptable. On turbo engines, however, due to fuel blow-by under boost, he recommends 6K changes with a new filter half way though. I personally have 8K on my peripheral port 13B GRM Challenge car, but that was just one trip over 2 weeks.

Short answer is, do what you're comfortable with, but you can rest easier knowing that synthetics do indeed last longer and perform better with no excessive carbon build-up.

BTW, Rob wanted me to warn you about mineral motor oils marketed for so-called higher mileage cars -- these contain petroleum solvents that swell seals. Two things can happen in a rotary: either the oil control seals swell up, bind and break (rebuild time!) or they don't, but then you are stuck using the product indefinitely as switching back is likely to cause excessive oil leakage.

gago

I have'nt switch back to dino yet..
took it for a drive and I notice my oil pressure is a lot higher (around 8) @ 4-5k rpm

It seems like the leak comes just underneath the water pump area and not the OMP...any thoughts?
Is there a "stop leak"I could pour in?
Also I notice that my main cat has oil driplets. It would explain why the car was smoking..

err....

FormerPorscheGuy

I switched to synthetic the last time I changed my oil, I am very happy with my decision to do so.

I recommend it to everyone.

gago

??

rotary-tt

Could be the dreaded front cover seal. $15 part and $1200 labor. When you lose this seal, you will lose enough oil to coat the cat and smoke you out of the car...

rick@ap

I had heard that Mobil 1 was no longer a fully syn. oil but a blend. The reason I had heard for the switch was that there competitors were advertising as a syn. oil but was only partially syn. This allowed there competitors to have a lower market price on oils. So in order to compete they switched over as well.

I haven't been able to verify any of this though but thought it was interesting. To put my own mind at ease I started using NEO which I know is a fully syn. oil

gago

I will look for something I could pour in to stop the leak and then run the car for a while then switch back to dino...

any suggestions on what kind of additive??

rynberg

That's crap -- Mobil1 is a full synthetic. All of the oil companies market "blended" oils at a price in-between their mineral and synthetic oils.

FormerPorscheGuy

MYTH