New guy needs RX8 (1.3) oil advice
06-25-2013, 08:57 PM
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New guy needs RX8 (1.3) oil advice
Sons RX8 starting to lose power... engine replaced by previous owner in 2006. I assume same plugs have been in it since then so Im going to replace them with NKG iridiums.
Im confused about what oil to use... I have heard the 5w is too thin...and the 10w is too thick for the oil injection....Help!
Im confused about what oil to use... I have heard the 5w is too thin...and the 10w is too thick for the oil injection....Help!
06-25-2013, 09:05 PM
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Oil injection with 20w50 is perfectly fine. It won't be too thick, so anything thinner will also be fine.
Mobile 1 0w40 has consistently returned the best oil analysis results from multiple owners doing used oil testing.
But largely, it's a decision you will have to make. The more people that chime in, the more opinions you will get.
https://www.rx8club.com/new-member-f...t-here-202454/
Mobile 1 0w40 has consistently returned the best oil analysis results from multiple owners doing used oil testing.
But largely, it's a decision you will have to make. The more people that chime in, the more opinions you will get.
https://www.rx8club.com/new-member-f...t-here-202454/
Which oil to use
The most debated question in the community, bordering on a religious war, so I won't try to cover every point here.
It boils down to deciding for yourself.
Some go with 5w20, to stay with Mazda's recommendation in North America. Some go with 5w30 to go with Mazda's recommendation outside North America. Others go to 10w40 or even 20w50, the most common weights among RX-7s. The general arguement revolves around if 5w20 is too thin or not. Typically, you want to go with a heavier weight oil (higher numbers) the hotter the environment you live in. Many manuals outside of North America state something to this effect. So research up on it, and make your own decision.
Dino vs synthetic is another hot topic, with the main arguement revolving around if the strength of the synthetic is worth the cost, and if there is any better burning (or not better burning) than dino oils, and if any deposits are left behind that could increase engine wear. Mazda only recommends non-synthetic, but does not require it. Your decision.
One point to keep in mind is that OIL WEIGHT AND OIL TYPE HAVE NO SIGNIFICANT IMPACT ON ENGINE FAILURE METHODS. In theory, the only way that oil weight could impact an engine failure is if it is a bearing failure. Oil weight has zero impact on the internal seal lubrication. Bearing failures are incredibly rare. In theory, the only way that oil type could impact an engine failure, is if you subscribe to the belief that injected synthetic is worse to burn than injected dino. This is belief based only. No one has been able to provide evidence for burn quality one way or the other.
And yes, all weights of oils mix with all other weights of oils, roughly averaging the numbers. Half 5w20 and half 5w40 is roughly 5w30, for example. Not precisely, but close enough. Dino also mixes entirely fine with synthetic.
The most debated question in the community, bordering on a religious war, so I won't try to cover every point here.
It boils down to deciding for yourself.
Some go with 5w20, to stay with Mazda's recommendation in North America. Some go with 5w30 to go with Mazda's recommendation outside North America. Others go to 10w40 or even 20w50, the most common weights among RX-7s. The general arguement revolves around if 5w20 is too thin or not. Typically, you want to go with a heavier weight oil (higher numbers) the hotter the environment you live in. Many manuals outside of North America state something to this effect. So research up on it, and make your own decision.
Dino vs synthetic is another hot topic, with the main arguement revolving around if the strength of the synthetic is worth the cost, and if there is any better burning (or not better burning) than dino oils, and if any deposits are left behind that could increase engine wear. Mazda only recommends non-synthetic, but does not require it. Your decision.
One point to keep in mind is that OIL WEIGHT AND OIL TYPE HAVE NO SIGNIFICANT IMPACT ON ENGINE FAILURE METHODS. In theory, the only way that oil weight could impact an engine failure is if it is a bearing failure. Oil weight has zero impact on the internal seal lubrication. Bearing failures are incredibly rare. In theory, the only way that oil type could impact an engine failure, is if you subscribe to the belief that injected synthetic is worse to burn than injected dino. This is belief based only. No one has been able to provide evidence for burn quality one way or the other.
And yes, all weights of oils mix with all other weights of oils, roughly averaging the numbers. Half 5w20 and half 5w40 is roughly 5w30, for example. Not precisely, but close enough. Dino also mixes entirely fine with synthetic.
There are 2 different "types" of oils (dino and syn)
There are 5 commonly available cold weights of oil (0, 5, 10, 15, and 20)
There are 4 commonly available hot weights of oil (20, 30, 40, 50)
There are 4 commonly available "Straight" weights of oil (20, 30, 40, 50)
So that means that there are (2 * 5 * 4) + (2 * 4) 48 different oil types/grades to choose from before you even get to BRAND of oil. I can think of 10 (Castrol, Valvoline, Mobile 1, Pennzoil, Royal Purple, Peak, Quaker State, Shell, Motorcraft, Mobile Super), bringing the number of options to 480.
Then we get into climate and driving conditions.
So even if you find that 1 person in 480 that you agree with 'in general', the climate conditions between you two are probably quite different, making an actual agreement unlikely.
And you know what the kicker is at the bottom of this whole oil debate pile?
It doesn't really matter
Fresh oil on regular changes is far far far more important than ANY of the above attributes. And the only impact that crankcase oil lubrication has on your engine's lifespan is bearing wear, which is not a severe concern for us, since we have numerous other methods of engine failure that have nothing to do with oil attributes!
Outside of lubricating the e-shaft bearings and being available for injection into the combustion chamber (where none of the attributes above matter at all), the oil's benefit is a secondary method of assisting to keep our engines cool. Oil is fantastic for transporting heat out of the engine. And all types and viscosity do that equally well, or as close to equally as won't make a tangible difference.
So if oil weight matters to you, then do some reading on the various opinions, find an opinion you somewhat agree with that is made in reference to the climate you drive in, the drive style you do, and your budget, and go with that.
There are 5 commonly available cold weights of oil (0, 5, 10, 15, and 20)
There are 4 commonly available hot weights of oil (20, 30, 40, 50)
There are 4 commonly available "Straight" weights of oil (20, 30, 40, 50)
So that means that there are (2 * 5 * 4) + (2 * 4) 48 different oil types/grades to choose from before you even get to BRAND of oil. I can think of 10 (Castrol, Valvoline, Mobile 1, Pennzoil, Royal Purple, Peak, Quaker State, Shell, Motorcraft, Mobile Super), bringing the number of options to 480.
Then we get into climate and driving conditions.
So even if you find that 1 person in 480 that you agree with 'in general', the climate conditions between you two are probably quite different, making an actual agreement unlikely.
And you know what the kicker is at the bottom of this whole oil debate pile?
It doesn't really matter
Fresh oil on regular changes is far far far more important than ANY of the above attributes. And the only impact that crankcase oil lubrication has on your engine's lifespan is bearing wear, which is not a severe concern for us, since we have numerous other methods of engine failure that have nothing to do with oil attributes!
Outside of lubricating the e-shaft bearings and being available for injection into the combustion chamber (where none of the attributes above matter at all), the oil's benefit is a secondary method of assisting to keep our engines cool. Oil is fantastic for transporting heat out of the engine. And all types and viscosity do that equally well, or as close to equally as won't make a tangible difference.
So if oil weight matters to you, then do some reading on the various opinions, find an opinion you somewhat agree with that is made in reference to the climate you drive in, the drive style you do, and your budget, and go with that.
06-26-2013, 12:57 AM
#8
I HATE SPEEDBUMPS!
06-26-2013, 07:45 AM
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Sons RX8 starting to lose power... engine replaced by previous owner in 2006. I assume same plugs have been in it since then so Im going to replace them with NKG iridiums.
Im confused about what oil to use... I have heard the 5w is too thin...and the 10w is too thick for the oil injection....Help!
Im confused about what oil to use... I have heard the 5w is too thin...and the 10w is too thick for the oil injection....Help!
RX-8 Recommendations | Pettit Racing
I have delt with pettit for a lot of my rx7 stuff, and they know rotarys, both the original 13b and the renesis. They say 10w40 or 20w50(race app), as well as quality synthetic. That being said I follow their recommendations and haven't had a problem out of my rotary motors.
06-26-2013, 09:10 AM
#11
Regular (2k-3k miles) oil changes are by far the most important thing to do. My 5w-20 comes out BLACK AS NIGHT after just 2k miles! I don't even get to do as much spirited driving as I would like to. Haven't tried different weights yet. Good news is that my engine is just about at the 60k mile mark, so no 5w-20 is not too thin for normal application. It has done me just fine so far! That being said, if you/your son does much spirited driving (or long instances of it), or live in a hot area, don't be afraid to increase the weight. It's pretty intuitive after a bit of research. Like Blk1.3 said, pettit racing offers many good recommendations for rotary cars. Race cars get hotter and do better with higher oil viscosity. It is really all up to you! Good luck!
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