The flash points of synthetics and mineral oils are about the same. Boiling point has nothing to do with it. Deposits are also about the same at about 1%. See: http://www.vtr.org/maintain/oil-overview.html

 

To answer your question: 5+ years on the FD(Redline) plus countless more with the FB and yes, the oil will definately burn off when injected. Compare the combustion temperature to the flash point. The higher flash point will provide more protection. Yes, the car smokes less and oil usage seems to be slightly higher in comparison to Castrol GTX.

Dis1: Please read the site you linked to. if you took a look you'd see that the good synthetics(such as Mobil 1 and Redline) leave ZERO deposits unlike conventional oils(which also have lower flash points)

 

mobil 1 FLASHPOINT C (F)DEG
Formula 0W-30
238 (460)
Formula 5W-30
235 (455)
Formula 10W-30
243 (470)
Formula 15W-50
245 (473)


quakerstate
5W-20
229(445)
5W-30
207(405)
10W-40
227(441)
10W-30
210(410)
20W-50
227(441)

i couldnt find castrol's flash points


pennzoil long life
15W-40
232(450)
10W-30
229(445)

theres a million brands of oil, personally i use castrol but i cant find its tec data on their site..with my new engine im gonna run mobil one, it took reading this to choose...roughly the mobil one's flashpoint s are between 5 to 50 deg higher than a similar grade of dyno oil..

473 def farenheight for the 15w 50, i dont know abt you guys but my engines combustion chamber is way hotter than that, a well tuned rotary runs abt 1200 deg farenheight exhaust gas temp...

all # were taken from their respective sites

hope that helps everone choose their oils now
len

 

asmoil

i dont know wich one e3veron runs so heres a bunch

AMSOIL XL-7500 SYNTHETIC 5W-20
230 (446)
AMSOIL Series 2000 Synthetic 20W-50 Racing Oil
234 (453)
AMSOIL 100% Synthetic 10W-30 Motor Oil
230 (446)
AMSOIL High Performance Synthetic 20W-50
236 (457)

 

JspecFD: Please don't be stupid. I did read the article! The --- means "data not available" or more to the point the writer just went to the various web sites and if the data wasn't provided he didn'y contact them for it. Or are you telling me Pennzoil Performax has a flash point of zero meaning it's always on fire and Exxon XD3 is like air and has no viscosity. Also in regards to flash points being higher I meant they are the same within reason. The difference between 460 (Pennzoil GT Perf) and 500 (Redline) isn't that big of a deal when you are talking the inside of a rotary engine's combustion chamber. They will both burn. So please people, stop getting on my case or I'll fire back

 

I don't believe deposits were ever the problem, only a rumor that got started some how. Also the sourse of the artice I originally quoted is a copy with synthetic info added. The original is from another site. Here is a little tid bit posted by David Lane on the big list:

After many years of discussion on this topic, I finally ran across
something from a manufacturer that addresses the history of the
issue directly.

My source was, believe it or not, a wall in the office at Sun Auto--a junk yard specializing in 1st and 2nd gen RX-7s. It is in the form of a letter written on Amsoil letterhead, and signed by someone in the Technical Services Department. The letter was written to a private individual, but it looks like a form letter, and I saw it in a public place, so there should be no harm in paraphrasing it here. I am working from a copy.

The letter says the reason Mazda did not recommend synthetic
oils was due to problems with the rotor seals (part numbers 0820-11-341 and 1202-11-343). The problems were apparent with "at least one" synthetic oil.

Amsoil had been sponsoring RX-7 racing since the '70's, and thus
had always been concerned with this.

When Mazda came out with their caution in 1988, Amsoil tested
for seal compatibility.

The letter implies that the seals in question were designed to swell as a means of replacing worn material and maintaining component integrety. The idea was to control this swelling within an acceptable range, which Mazda specified as being between ten and twenty percent.

Amsoil used Pennzoil 10-30 as a reference and measured an 18.5
percent swell rate. Several Amsoil multi-weights were tested and
found to range in "swell rate" between 14.5 and 17.3 percent.

The following line is a direct quote:

"Since that time, Mazda has rescinded their recommendation not
to use synthetic oil in the Rotary engine."

End of paraphrase.

Now, this letter is dated September of 2000, and the notion that
Mazda didn't caution against using synthetics until 1988 was
enough to send me scurrying to the owner's manual for my 1985
GSL-SE. No mention of synthoil there--nor in the shop manual.
The only requirement is an SD, SE, or SF oil.

The last line--that Mazda had recinded their anti-synthoil stance--
was also a shocker. I would have assumed any information like
that would have hit this list like a clap of thunder. Of course, I am
in no position to confirm the assertion, or to argue with it.

Nothing above is going to change anyone's mind about the issue,
but it does tend to reinforce some of the points made in past
discussions, and to put things in historical perspective.

If anyone has a direct source to verify the notion that Mazda
currently has no prohibition against using synthetics, I would like to know about it. Last time I saw a Mazda reman in a crate, I
THOUGHT I saw a tag on it with a warning that using synthoil
would void the warranty. (Note: these engine seem to have about a dozen tags tied on them when delivered. You'd think someone would save time and energy by supplying a detailed instruction sheet instead.)

And, of course, there are no rotary cars currently in the United
States with original engines still under warranty, so the point is
moot from that perspective. We'll have to see what happens when the new rotary cars hit the showrooms.

Best wishes,
David Lane
-----------------------------------
Oh great, I hope this evidence doesn't make me look even more "holier than thou" Oh well, I'm only trying to contribute. Always feel free to question my thoughts on issues but when people get sarcastic in their remarks like "If ya had read the article you posted" I will return with the same sort of sarcasm. Well.... unless you are right at which point I'll just feel stupid and shutup:p

 

since on DINO oil, most of us run 20w 50 Castrol GTX, when switching to synthetics, would you be running the same weight?

Not to start a debate, but since I change my dino oil every 1000 miles, would switching to synthetic help at all? Or just a waste of $ since i change so often?