We've been discussing this phenomenon in this thread tonight......
https://www.rx8club.com/showthread.p...626#post586626

 

Well, if he gets to ask about motor oil, I get to ask the Most Asked Questions of All Time...

Should I be worried about flooding?
Why is the mileage so crappy?
How much should I pay for an RX-8?
Do I really have to use 91 octane?
Should I get an RX-8, a G35, or <insert name of popular sports car here>?

And don't tell me to use the search! I'm not using the search! Not until someone rudely tells this guy to search "oil" am I using the search!

 

Count me in as one that uses Castrol. I take my car in for oil changes, but when it needs extra oil I use Castrol. I have nver been a fan of Pennzoil.

 

Well, I hear you quack. These forum's are interesting no? Just ignore those who tell you to search. Most people (like me also) like to view the most recent threads. If a subject comes up again and again, hey, wonder why...it's because of a popular topic that interests all/many and makes for great discussion/debate. I use the search from time to time, but when I want to start a new thread on an old topic and somebody says "moron...just go search" I kinda chuckle and just keep on with the thread at hand. The oil topic makes for great threads...no reason not to start another one and keep the debate alive

 

while I get my free changes, the dealer will likely keep using "Mazda" 5w20. My sources tell me Castrol is in the black Mazda bottle. Historically as reported by Consumer Reports for about the past 25 years Castrol generally holds it's intended viscosity better than most other brands. OTH, oils are much better than they were back in the 70s so you almost can't go wrong with any brand if you keep it changed. That said, I'll be scanning the shelves for 0w30 and do some research into that and at a future date perhaps use that (Castrol 0w30 that is) when I do my changes in the 8 and mabye for the Miata and the van. I'm open to developments in oil technology. But I'll keep with non-syn in the 8.

 

My vote is for Castrol. trouble free miles ... 127,000 miles Millenia S, 148,000 miles '88 FC,

While the type of oil one uses is important, regular oil/filter changes are the key to engine longevity especially with our rotary engine.

 

ahhh the millenia S, love the thing, why no Miller Cycle in manual ?

 

I bought mine in 95. Wish it had a 5 speed manual or at least a 4sp slushbox with overdrive. the 3sp auto with overdrive is not well matched to the engine. Mine has Pearl paint still looks new... awesome oem paint job. A true Stealth machine.

 

we have a 98 millenia S in the family, one thing I love is the gas mileage is amazing, sometimes I'm getting 36mph or more on a tank and I'm not even driving like an old lady

the efficiency of the miller cycle is stunning, to bad no other car manufacturers like to take gambles like Mazda does (a rotary and a miller cycle in their lineup, amazing)

 

Historically, Pennsylvania crude oils have a much higher 'wax' content that crude oil produced in Texas, Canada, Middle East ... almost anywhere else. With traditional refining, motor oils produced from Pennsylvania crude oil still contained much higher wax content than motor oil produced from any other crude oil. That wax invariably resulted in sludge build-up. Pennsylvania crude was the source for Pennzoil (hmm, how about that! ), and Quaker State motor oils.

This is less of a problem these days due to two factors - Pennsylvania does not produce very much crude oil anymore, and the refining processes are significantly improved. Still - I will never use either of those brands in any car I own.

(background - I spent 10 years as a petroleum engineer working for Texaco Canada Resources - downstream, not in refining, but word gets around!)

Regards,
Gordon

 

Full Synthetic!!!!! Royal Purlple! well thats what i have, tranny and diff too, makes a huge deference

 

How about this oil from Re Amemiya - full synthetic.

http://www.re-amemiya.co.jp/new_part...03_na_oil.html

 

So what do you use?

 

I would tend to agree with your statement that it's less of a problem today. I bought a Ford Explorer new in early 1991. I ran Pennzoil in it exclusively until I sold it 3 years ago with 125,000 miles on it. 30,000 of those miles were with four souls onboard (not counting our Lab) and pulling a 2000 lb. tent-trailer across some of the hottest deserts in the western states and into the Rocky Mountains and Sierra Mountains. I had to pull both cylinderheads at 97,000 (one had a very small crack, resulting in slight coolant usage. Early Exploders were known for this problem). Anyway, it was interesting to note that the camshaft and cam followers looked like new and there was no noticeable ring-ridge in the cylinders. Also, I saw no evidence of sludge or buildups under the valve covers or any other of the exposed parts. It was very clean. I suppose there could've been something in the oil pan, but after seeing the excellent condition of the upper end of the engine. I wasn't too worried.

1.3L

 

I use Valvoline oil. I change my oil between 3000 and 3500 miles. The oil still looks good when I chamge it.

 

All HIGH quality conventional motor oils are Parafin based. Parafin means wax BUT NOT in relation to motor oils. People hear parafin based oil and think wax based NOT true. ALL conventional motor oils are parafin based. Pennsylvania sweet crude was at one time the best oil base for motor oils. It required the least amount of refining to be used in that application. The sludge problem that people talk about with oil has no relation to the the base stock of the oil itself it is from the additives. It was caused not buy any brand, in reality it was caused by the weight of oil used. An example 10w40 oil has to cover a large range to meet the 10 weight when cold and the 40 weight when warm. They use an elastomer additive in oil that expands with heat to make it act as the thicker viscosity when warm. To cover such a large range the oil needs ALOT more additives. A 10w40 oil is 30% to 50% additives to meet that range. A 10w30 oil is (roughly) 5% to 15% to meet its range. The elastomers are the cause of sludge they break down fairly fast. Oil itself does not ever break down or wear out it gets contaminated and the additives wear out. NO company uses recycled oil without charging you EXTRA for it as it is more expensive to re-refine used oil. Reguarding the color of say Penzoil out of a bottle here is a little tidbit if info reguarding pennzoil.

One of the recent advancements in motor oil technology relates to the further refining of conventional base oils by removing virtually all contaminants and impurities. Progress has also been made with synthetic blends, which are formulated from combinations of conventional and synthetic base oils.

Pennzoil Products Company's Multiviscosity Motor Oil is blended with PureBase, a new proprietary base oil. "Pennzoil is the only motor oil to use this ultra-pure base oil in all of its multiviscosity motor oils," Courtneye B. Wolf, coordinator of marketing communications for Pennzoil, said.

Base oil, the primary ingredient in engine oils, is refined from crude oil through a series of separation and purification processes. One of the most important steps performed during refining, according to Wolf, is increasing the base oil's stability. In a refinery, base oils are stabilized by processes that increase the degree of saturation and remove sulfur and nitrogen compounds. There are two major stabilization processes currently in use today: solvent extraction and hydrocracking.

Solvent extraction is an older, less effective process than hydrocracking, Wolf said. "This process involves mixing the oil with a special solvent that is not soluble in the oil, but does dissolve some of the contaminants and impurities common to all crude oil: namely, unsaturated nitrogen and sulfur compounds. The major drawback has been that the solvent extraction process only partially removes contaminants and impurities. Typically, about 78 percent of the resulting oil is pure, while the remaining 22 percent is composed of contaminants and impurities."

The process used to manufacture PureBase, hydrocracking, involves heating the crude oil to more than 700 degrees Fahrenheit in the presence of 3000 psi of hydrogen gas and a catalyst. Hydrocracking removes sulfur and nitrogen, opens carbon rings into straight chains and saturates the oil. The result is a base oil that is 97 percent pure, with virtually all contaminants and impurities removed.

WAY to much info there HEHE

The dark color of Pennzoil comes from the additive package 1 additive is black and makes the oil darker, it also is the first thing you smell if you open a bottle and take a wiff. With the new GF-4 spec for oils you honnestly cant buy a bad oil the standard for the spec is just to high.

Well more info then you all wanted in shure but maby somone will find it usefull or intresting. And NO im not telling anyone to use Pennzoil (i dont) just used them as an example.

 

I tried Pennzoil 5/20, and I found that it caused my car to run a little less spin happily than the Castrol. I use only Castrol now, which seems to be working very well.