the June issue of Hot Rod magazine (p 125) contains an article entitled: "When Good Cams Go Bad." while the report discusses an alarming 3 year trend in camshaft/lifter failures the significance of the primary culprit probably should be considered by all rotary owners. Anti wear is at least as important if not more so for the rotary.



a major engine builder is quoted as seeing more camshaft/lifter failures in the last 3 years than the prior 30.



while a number of reasons are considered one of the key conclusions is the recently reformulated standards for motor oil.



unfortunately i wasn't able to copy the article but here's an executive summary:



approx 4 years ago the auto manufactures, oil companies and the government (always bad to get them together) met to discuss an issue the regulators had re the effects of the PRIMARY ANTI-WEAR ADDITIVES in oil and their effects on catalytic convertor life.



the additives are primarily zinc and phosphorus (referred to as ZDDP) they act as sacrificial items and take the mechanical wear in lieu of the engines components.



due to the fact that todays motors use roller rockers the industry didn't need as much wear protection as in the past and capitulated.



the article features a table showing % of the 2 elements going from .13% in 1996 to .087 in 05 (Zinc) and .12 (Phosphorus) to .08 in 05.



rotary engines NEED these additives. the law going forward removes more ZDDP until there is almost no remaining ZDDP.



Racing Oil does not fall under the restrictions.



Quaker State Q Racing, for example, contains .2 of Z and .18 of P. Over the road trucks are exempt until 07. you can buy Shell Rotella T at Walmart (Truck oil) and it contains .14 and .13. Pennzoil Racing oil is .196 and .18.



i have used Mobil One since 1983 and will be checking w them tuesday to find out what the specs are.



you can tell which oils have reduced wear additives.... a Gold Starburst label and designation ILSAC GF-4. it is safe to conclude all non racing ex-trucks oils now fall into the no no category.



rotary owner had best steer clear of street legal oils.



another option is to add GM Camshaft and Lifter Prelube PN12345501 4 ounces about $6 at the time of your oil change.



i pass this info on, knowing it's importance to the rotary community and of course looking for additional input.



there is perhaps no subject w more written about it than oil. i hope that there will be no posts on this thread about loving some type of oil. let's focus on ZDDP and add additional info here as rotaries need all the antiwear they can get .



going forward i will make my choice of oils based on ZDDP content.



howard coleman

Good info Howard. Please post the mobil 1 findings when you get them.

Thanks!

I run shell Rotella T in the rx7.

I run Redline 5W30 in my 03 legacy GT. I wonder what redline has in it's formulations

Daft question, but where is the evidence that rotaries need these additives. I can't initially see the relationship between cam wear and anything in the engine.

if you are worried put a swag of premix into the gas tank at each fill up. That in conjunction with the stock OMP should be more than enough lube for your engine. If you are worried about too much oil causing smoke, my lawnmower takes a ratio of 1:32 and it does not smoke a bit.

so what oil is used in the rx8?

I read the article that he's talking about and it also says that diesel motor oils have more ZDDP in them so that's good.... But they also have more detergents and when they burn they leave behind some byproducts that makes detonation easier to take place. That being said I still run the Rotella T in my car. I don't have a omp so I don't worry about burning all that much motor oil.

I saw that article and thought the same thing...

(IMO) Rotarys need there oil changed more often then piston engine's. If you want them to last.. Everyone knows that rotarys biggest enemy's are: Heat, DIRT and of course detonation..



I change my oil at least every 2,000 miles to slow down wear caused by particles in the oil. so anything that helps with anti-wear is a big plus in my book...

5w-20