Changed Oil - Big Difference! Anyone Else Notice This?
02-21-2011, 08:48 AM
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Changed Oil - Big Difference! Anyone Else Notice This?
I've had my RX-8 for a little over a month now and I've loved every minute. There is something amazing about driving this car. I decided to change my oil last weekend from the standard stuff that Mazda put in there, to Royal Purple Synth 5w-30.
Once I had the new oil in I went for a spin. I have never seen a major change in how an engine sounds and revs from just an oil change, but then again I've never owned a rotary before.
The engine revs MUCH smoother than before. It's quieter, smoother, and seems to rev more freely. It was almost a night and day diff. I had driven the car around all morning running errands, and then after the oil change it was like the engine was brand new again.
Has anyone else every noticed this when going from the standard 5w-20 dino oil to a fully synthetic?
Once I had the new oil in I went for a spin. I have never seen a major change in how an engine sounds and revs from just an oil change, but then again I've never owned a rotary before.
The engine revs MUCH smoother than before. It's quieter, smoother, and seems to rev more freely. It was almost a night and day diff. I had driven the car around all morning running errands, and then after the oil change it was like the engine was brand new again.
Has anyone else every noticed this when going from the standard 5w-20 dino oil to a fully synthetic?
02-21-2011, 09:06 AM
#5
Rotary Engine FAQs:
Can Royal Purple Motor Oil be used in a rotary engine?
Yes. A rotary engine is a modified four-cycle engine that recommends the use of an API-licensed motor oil for street applications.
More information and FAQs on lubrication of rotary engines.
In a rotary engine, the oil lubricates the eccentric shaft bearings, thrust needle bearings and rotor bearings (similar to a crank and rod bearing of a piston engine). It also is injected into the combustion chambers to lubricate the apex seals, corner seals, and side seals, all of which helps to create the sealing mechanism (the equivalent job of the piston rings).
Royal Purple provides outstanding protection for the e-shaft, rotor bearings and thrust bearings and is suitable for the oil injection system as it has proven to run cleaner than other oils and is an excellent choice for rotary apex seals, corner seals and side seals.
Mazda makes a statement in the Owner’s Manual not to use synthetic oils in a rotary engine, why do you say that it is OK?
Royal Purple has performed seal compatibility testing on the components used in a rotary with excellent results — including older rotary engine seals dating back to the Cosmo. Royal Purple’s Technical Services Manager David Canitz (who has been an owner and racer of rotary engine cars using synthetic motor oils since 1985 with excellent results) has been trying to find an answer to this Mazda statement for the last 18 years.
In the early development of synthetic oils decades ago, there were purportedly some seal compatibility issues. Today’s synthetic oils do not have the compatibility issues of the old oils. There is no substantiated evidence of seal compatibility issues with Royal Purple.
Here are some facts:
•The Mazda Factory racing departments recommend and use ‘synthetic’ oils including the winning 1991 Leman’s 20-G 4 rotor Mazda 787B.
•MazdaComp USA printed manual (now Mazdaspeed) recommends the use of synthetic oils for racing conditions.
•Royal Purple Motor Oils have been used in rotary engines (both race and street) for 10+ years with excellent results.
•Royal Purple Motor Oil is compatible with the bearing material, sealing elastomers and combustion seals used in a rotary engine.
I heard that synthetic oil doesn’t burn like mineral based oils and will coat the inside of the engine with deposits. Is this true?
If this was a problem with synthetic motor oils in general, then all internal combustion engines using a ‘synthetic’ would experience increased deposits on internal surfaces. The opposite is actually the norm.
Conventional four-cycle motor oils will typically leave deposits of carbon and ash when injected into the rotary apex seal, corner seal and side seal areas. Royal Purple’s motor oil burns cleaner due to its synthetic base stock being free of contamination and the fact that many of its additives are ‘ashless’. This may not be true for all synthetics but Royal Purple has been proven to work extremely well in rotary engines.
Royal Purple’s formulation of synthetic hydrocarbon motor oil burns at the nominal combustion temperatures experienced in both street and racing applications, whether normally aspirated, turbocharged or supercharged. (500 – 1700%°F idle to race rpms typical combustion temps)
Will the synthetic oil affect the oil seals?
No. Royal Purple’s motor oil is fully compatible with the elastomers found in rotary engines as well as more conventional piston engines. The oil seals, housing seals and other elastomers used in rotary engines typically consist of Buna N, Nitriles, Neoprene or Viton materials, which are also commonly found in piston engine cars.
I hear that synthetic is ‘thinner or lighter’ oil. Is there a greater possibility that the oil will leak between the seals?
No. If an engine’s sealing surfaces are in good condition, synthetic oil should not cause any leakage. However, if an engine has marginal seals, there is a 50/50 chance the seals will leak. A synthetic motor oil is going to have similar viscosity to that of a conventional motor oil – except at extreme temperatures. Due to a flatter viscosity curve, at low temperatures it will not thicken as much (easier winter cranking) and will not thin out as quickly at higher operating temperatures (better oil film at higher rpm).
02-21-2011, 09:24 AM
#9
Congrats on the oil change 
The big difference is probably due to your suggestion but you did the right thing.
Some new members keep spreading false informations that come from their (wrong) beliefs, you'll learn to pick everything with a grain of salt with time.
The big difference is probably due to your suggestion but you did the right thing.
Some new members keep spreading false informations that come from their (wrong) beliefs, you'll learn to pick everything with a grain of salt with time.
02-21-2011, 09:27 AM
#10
BTW FWIW, I did notice a good difference in oil pressure values when switching from dino 5w30 to rp 5w30. My idle numbers seemed a bit stronger and stable and my top end pressures looked more like the mazda spec. PSI's were kinda low when using the dino.
02-21-2011, 09:29 AM
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Actually I have read the owners manual. I also did several weeks of research on the whole synth vs regular oil before making my decision.
There are people who have run full synth without any problems. It's is my belief (and also my car, so I'll do as a I please) that synth is not the devil that a lot of people make it out to be. It's just not fully tested by Mazda and so not endorsed as a usable oil type.
But until there is some hard, concrete evidence that synth destroys these engines, then I feel safe using it. Besides, I'll most likely have the SOHN oil pump mod done within the next 2 months so I'll be using 2 cycle Idemitsu from a seperate resevoir before long. Case solved.
There are people who have run full synth without any problems. It's is my belief (and also my car, so I'll do as a I please) that synth is not the devil that a lot of people make it out to be. It's just not fully tested by Mazda and so not endorsed as a usable oil type.
But until there is some hard, concrete evidence that synth destroys these engines, then I feel safe using it. Besides, I'll most likely have the SOHN oil pump mod done within the next 2 months so I'll be using 2 cycle Idemitsu from a seperate resevoir before long. Case solved.
02-21-2011, 09:31 AM
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Wow, really? I mean Really? It's freakin' oil man. Get it tested after 5,000 miles and see how great it is, then you can claim it. Good idea on the SOHN though and running synthetic.
Last edited by 9krpmrx8; 02-21-2011 at 09:43 AM.
02-21-2011, 09:32 AM
#13
Actually I have read the owners manual. I also did several weeks of research on the whole synth vs regular oil before making my decision.
There are people who have run full synth without any problems. It's is my belief (and also my car, so I'll do as a I please) that synth is not the devil that a lot of people make it out to be. It's just not fully tested by Mazda and so not endorsed as a usable oil type.
But until there is some hard, concrete evidence that synth destroys these engines, then I feel safe using it. Besides, I'll most likely have the SOHN oil pump mod done within the next 2 months so I'll be using 2 cycle Idemitsu from a seperate resevoir before long. Case solved.
There are people who have run full synth without any problems. It's is my belief (and also my car, so I'll do as a I please) that synth is not the devil that a lot of people make it out to be. It's just not fully tested by Mazda and so not endorsed as a usable oil type.
But until there is some hard, concrete evidence that synth destroys these engines, then I feel safe using it. Besides, I'll most likely have the SOHN oil pump mod done within the next 2 months so I'll be using 2 cycle Idemitsu from a seperate resevoir before long. Case solved.
02-21-2011, 09:46 AM
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I dont see how it would be so outlandish to see smoother operation of the engine with a higher quality, thicker synthetic oil vs the stock stuff. Maybe I'm more sensetive to these types of things than some people, but I can tell you that there is definitely a difference. Believe what you will. It was most noticable from 4k up to redline, but my idle also seems smoother.
okay. 
02-21-2011, 10:12 AM
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Exactly. Me too
Royal Purple is okay oil but don't believe the hype (of any oil companies claims).http://www.deluxeoil.com/royal_purple_claims.htm
02-21-2011, 10:23 AM
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You know the insulation in my attic, the manufacturer's website says its OK to breathe the fibers! (too lazy to insert smilie)
02-21-2011, 10:25 AM
#19
Post up pics of your 8! and heres a link to where the chicago people hang out at
http://www.evolvchicago.org/phpbb/index.php
http://www.evolvchicago.org/phpbb/index.php
02-21-2011, 11:31 AM
#20
Of course if somebody came here claiming that with a 20w50 oil during winter the car feels sluggish it would be a different story (not necessarily, it's just an example).
I like your approach anyway and i've been using synthetics since i first got the car. That's why i told you to take everything with a grain of salt, some members were just spreading the ol' bullshit of minerals etc.
9krpmrx8 just made what I said clearer, no need to step up!
02-21-2011, 12:30 PM
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Post counts don't mean much, the fact is that we've all been there and have done that before. It's true that the car feels smoother but it's something minimal performance wise.
Of course if somebody came here claiming that with a 20w50 oil during winter the car feels sluggish it would be a different story (not necessarily, it's just an example).
I like your approach anyway and i've been using synthetics since i first got the car. That's why i told you to take everything with a grain of salt, some members were just spreading the ol' bullshit of minerals etc.
9krpmrx8 just made what I said clearer, no need to step up!
Of course if somebody came here claiming that with a 20w50 oil during winter the car feels sluggish it would be a different story (not necessarily, it's just an example).
I like your approach anyway and i've been using synthetics since i first got the car. That's why i told you to take everything with a grain of salt, some members were just spreading the ol' bullshit of minerals etc.
9krpmrx8 just made what I said clearer, no need to step up!
I was just being a tad sarcastic. I've actually read some very informative stuff from some of you while doing my research and I have a lot of respect for the people here. I think I pretty much read all of the stickys in every section so far. Yeah, even some of the 100 and 200+ page posts.... lots of stuff to dig through. I've havent been new to a car community in a long time... I have been a DSM'er for well over 10 years (well before fast and furious too). I still have my original 1992 eclipse sitting in my garage with a blow head gasket. It'll be my spring project and most likely get sold once fixed. I also owned an Evo 8 for several years... sold it for the RX8 in January. My evo was heavily modded... too much to be a good street car anymore. I wanted something that was sporty and better for daily driving. The RX8 answered the call.
Honestly, I'd trust almost any name brand fully synth oil. I haven't tried royal purple before and I've heard good things from many people for years. I figured I'd give it a go this time around. I just want to be consistent with my choice of oil from the start.
