this might help... here:

 

Hey, you can follow what every guidelines you want... but based on how I have seen oils contaminated, I use 5K miles or 3 month oil replacements (which ever comes first) regardless of what oil I am using.

 

rotaries burn oil....they are designed to......

if you dont want to change it often....atleast check your levels to make sure you are not starving your rex...

 

They're also talking about piston engines, are they not? It's a bit different for a rotary. You should check your oil AT LEAST every 1,000 miles to make sure it stays topped off. It wouldn't hurt to check it everytime you fill up with gas.

The difference in cost of changing the oil every 3-5k instead of every 25k is well worth the extra protection it will give your engine by keeping the oil fresh.

 

I highly doubt that Amsoil would market this and not have done reasearch to prove it. They do not sell snake oil. Besides, other than injecting oil into the combustion chamber a rotary is no different than a piston engine in the way it uses oil. It has bearings just like a piston engine.

James

 

oh dont think im trying to prove you wrong or anything like that, i wasnt trying to be hostile or anything in any way, i was just trying to figure out what i should do if i go synthetic

 

Icemark, have you heard of the Motor Oil Bible? It comes with supposed test specs on many different oils. You said Valvoline synthetic sucks.. but in the bible, the 10w30 Valvoline scores very close in this order: Redline, Amsoil, Neo, Valvoline, Havoline, Chevron, etc.. with Mobil 1 surprisingly down further under a few more brands. But there's only 60 pts between the Redline and the Mobil 1, out of 762 maximum that Redline scored. That was redline 30wt race only oil though, the normal 10w30 Redline scored right above the Mobil 1 with 710pts, but the specs on the Redline are from 4 years ago. Pennzoil actually scored the worst out of the synthetics, behind many of the petrols.

It also gives ash content for many of the oils, all of the oils, synthetic or not, have an ash content somewehre between .6 and 1.6% Of course for many of the oils it doesn't give the ash content, but I would think that with only a 1% ash content difference in all the oils, could it really make that much of a difference?

Also, some examples of the ash content %'s given, all still in the synth 10w30 category:

Amsoil ~1%
Neo 1.03%
Valvoline 1.1%
Havoline 1.1%
Chevron 1.11%
Mobil1 1.2%

They didn't say what Redline's ash content was though.
And on a random site I found it says <0.4% for Amsoil.

 

Yeah that is the problem with some of the old tests... they take info from the 90s and expect it to be the same as currently.

Almost every oil out there has been reformulated in the last 5 years, so if a test is still referring to mixes that old I would question the pertinence.

I guess I need to post up on my website the current specs I have and create my own sheet

 

Icemark,

I'm sure this has been covered before but you are the resident FC expert - can you use synthetic in a motor thats only run on conventional oils for the length of it's life? Is there any advantage or disadvantage? I run Castrol 20W50 all year round for as long as I can remember...castrol (non synthetic) has always been the shop preference in oils.

 

I hardly think of myself as a FC expert... Just well versed

The only disadvantage that I see in using a better quailty (read low ash, low deposit) synthetic oil, at any point after break in, is the cost of the synthetic.

It's pretty hard for me to justify paying so much for oil (I have three cars and the FC uses the least amount of oil in the pan as all of them). As mentioned above, I change the oil every 3-5K miles in each car regardless of type.

The only time I can justify the use of a synth to my pocket book is when the car is used for track or auto cross racing, where you want every advantage you can get.

 

thanks...now since quality synthetics produce less deposits, should those who are goign in for emissions inspections use synthetic? sometimes these cars need all the help they can get I re-install my high flow cat and airpump before each annual inspection...what a pain!!

 

IIRC, the oil viscosity chart shows that 20W-50 is good for temps as low as 20 F.

Hot_Dog
90 RX7 GXL
02 Acura RSX-S

 

You should do that, since some of the oil specs in mine are as old as 1991! That one was a brand I've never heard of though. Most of the important ones have specs from around 01-03..

 

The basis of his "neandering" thoughts is that not all "synthetic" oil is made from the same base stock. Castrol Syntec is made from Group III base stock, which is basically a glorified version of regular motor oil (Group II and IIa) as opposed to a true (in the traditional sense of the word) synthetic oil made from Group IV (PAO) base stock. Mobil sued Castrol because they felt that the "synthetic" label on Syntec was misleading, but the council unfortunately determined that the term "synthetic" was a marketing gimmick rather than an indication of any given product, so Castrol was allowed to keep the label. What you guys need to understand about a Group III oil is that although it has a lot of properties similar to Group IV synthetics, it does not have the same low-temperature characteristics or shock resistance, and it burns off faster.
http://www.oilsandlube.com/synthetic...ts_all_new.htm

 

I agree completely. The way i see it, if you change your oil regularly u'll be throwing away a lot of money.