Oh God....another synthetic oil decision?
Thread Starter
Rx7 and now Rx8
Joined: Jun 2006
Posts: 142
Likes: 0
From: Tucson, AZ
Oh God....another synthetic oil decision?
And yes...I've been through the Sticky since I bought my '06.
From the get-go my gut told me BS...I should run synthetic from day one. After reading all the 04-05 engine failures my mind said I better cover my axx and run non-Syn.
So it's 83K miles later...trouble-free car...I red line the thing 10-20 times on each trip out...I'm a nut and love this car.
I've know this friend who makes a living building all kinds of super high HP engines for various cars. HUGE buck engines. Here's what he told me the other night:
*You should have been running already or change to synthetic ASAP. Kendall is the best though Mobil 1 is OK. The Kendal thing is based on 30-years of builds and teardowns and inspections. It's the only oil they will use in their builds.
*No dealer can tell whatsoever that you're running synthetic unless they send the oil out for testing which they won't do because it costs too much.
*At my mileage he suggests 5-30 or even 10-30 because of internal wear and the fact we're in Arizona where it's warmer.
So.....my guts says screw it...I'm a synthetic everything guy...time to change!
Is he correct in his statements?
From the get-go my gut told me BS...I should run synthetic from day one. After reading all the 04-05 engine failures my mind said I better cover my axx and run non-Syn.
So it's 83K miles later...trouble-free car...I red line the thing 10-20 times on each trip out...I'm a nut and love this car.
I've know this friend who makes a living building all kinds of super high HP engines for various cars. HUGE buck engines. Here's what he told me the other night:
*You should have been running already or change to synthetic ASAP. Kendall is the best though Mobil 1 is OK. The Kendal thing is based on 30-years of builds and teardowns and inspections. It's the only oil they will use in their builds.
*No dealer can tell whatsoever that you're running synthetic unless they send the oil out for testing which they won't do because it costs too much.
*At my mileage he suggests 5-30 or even 10-30 because of internal wear and the fact we're in Arizona where it's warmer.
So.....my guts says screw it...I'm a synthetic everything guy...time to change!
Is he correct in his statements?
Last edited by ShottsCruisers; Aug 25, 2011 at 03:36 PM.
Shotts:
here's the problem with your scenario
- There is no way to tell whether switching to Synthetic at this point will make a difference. If we cloned your motor, installed it in another RX8 and ran that with non-synthetic under the exact same conditions as your current motor being switched to Synthetic only then could we have a side by side comparison.
What is your compression now?
I ask because what if it's already low, you switch to synthetic and then your motor fails in 10,000 miles.
Will you blame the change in motor oil? Maybe and that failure most likely was not caused by the oil but rather an engine that was already losing compression.
Your motor might be running "trouble free" right now but that isn't always the best indicator of compression. Ask me, I know.
My motor runs like a CHAMP, has consistently been one of THE highest whp motors at every dyno day I host (I've dyno'd hundreds of 8's over the years) and yet I know for a fact that my rear rotor is below the acceptable tolerance and my front rotor had 1 face failing and the other 2 are within 2 psi of failing.
Oh, and those compression results are over 18 months old and my car still runs like a beast yet I would venture to guess that over that time my compression has continued to drop.
Not bragging at all, simply sharing my experience that how a car 'feels' isn't always the greatest indicator of engine health.
You're right, dealers can't tell if you run synthetic or a different weight oil. My advice to people, "STFU and don't volunteer that info if the dealership doesn't ask for it." And if they do.... "I always just run whatever the manual says"
as for the weight: Higher temp areas will probably benefit from 5w-30 or higher.
here's the problem with your scenario
- There is no way to tell whether switching to Synthetic at this point will make a difference. If we cloned your motor, installed it in another RX8 and ran that with non-synthetic under the exact same conditions as your current motor being switched to Synthetic only then could we have a side by side comparison.
What is your compression now?
I ask because what if it's already low, you switch to synthetic and then your motor fails in 10,000 miles.
Will you blame the change in motor oil? Maybe and that failure most likely was not caused by the oil but rather an engine that was already losing compression.
Your motor might be running "trouble free" right now but that isn't always the best indicator of compression. Ask me, I know.
My motor runs like a CHAMP, has consistently been one of THE highest whp motors at every dyno day I host (I've dyno'd hundreds of 8's over the years) and yet I know for a fact that my rear rotor is below the acceptable tolerance and my front rotor had 1 face failing and the other 2 are within 2 psi of failing.
Oh, and those compression results are over 18 months old and my car still runs like a beast yet I would venture to guess that over that time my compression has continued to drop.
Not bragging at all, simply sharing my experience that how a car 'feels' isn't always the greatest indicator of engine health.
You're right, dealers can't tell if you run synthetic or a different weight oil. My advice to people, "STFU and don't volunteer that info if the dealership doesn't ask for it." And if they do.... "I always just run whatever the manual says"
as for the weight: Higher temp areas will probably benefit from 5w-30 or higher.
Last edited by Jedi54; Aug 25, 2011 at 03:46 PM.
The X is silent
Joined: Mar 2011
Posts: 688
Likes: 2
From: New Lebanon, Ohio
Well, you've read the stickies, so that's a good starting point. I'll just sum things up.
The reason that this argument exists is because of the OMP - the pump that sends oil to your apex seals. ANY oil that resists breakdown under high temperatures is going to be problematic for use in your car. If your oil doesnt break down when detonated, it will be problematic, so:
Ask your friend how much experience he has running that stuff in 2-stroke motors.
This is why people use the Sohn adapters... The apex seals get clean-burning 2-stroke oil, and the rest of the motor can use whatever synthetic your heart desires.
The reason that this argument exists is because of the OMP - the pump that sends oil to your apex seals. ANY oil that resists breakdown under high temperatures is going to be problematic for use in your car. If your oil doesnt break down when detonated, it will be problematic, so:
Ask your friend how much experience he has running that stuff in 2-stroke motors.
This is why people use the Sohn adapters... The apex seals get clean-burning 2-stroke oil, and the rest of the motor can use whatever synthetic your heart desires.
Registered
Joined: Aug 2006
Posts: 5,027
Likes: 5
From: Northern Virginia
Thread Starter
Rx7 and now Rx8
Joined: Jun 2006
Posts: 142
Likes: 0
From: Tucson, AZ
Shotts:
here's the problem with your scenario
- There is no way to tell whether switching to Synthetic at this point will make a difference. If we cloned your motor, installed it in another RX8 and ran that with non-synthetic under the exact same conditions as your current motor being switched to Synthetic only then could we have a side by side comparison.
What is your compression now?
I ask because what if it's already low, you switch to synthetic and then your motor fails in 10,000 miles.
Will you blame the change in motor oil? Maybe and that failure most likely was not caused by the oil but rather an engine that was already losing compression.
Your motor might be running "trouble free" right now but that isn't always the best indicator of compression. Ask me, I know.
My motor runs like a CHAMP, has consistently been one of THE highest whp motors at every dyno day I host (I've dyno'd hundreds of 8's over the years) and yet I know for a fact that my rear rotor is below the acceptable tolerance and my front rotor had 1 face failing and the other 2 are within 2 psi of failing.
Oh, and those compression results are over 18 months old and my car still runs like a beast yet I would venture to guess that over that time my compression has continued to drop.
Not bragging at all, simply sharing my experience that how a car 'feels' isn't always the greatest indicator of engine health.
You're right, dealers can't tell if you run synthetic or a different weight oil. My advice to people, "STFU and don't volunteer that info if the dealership doesn't ask for it." And if they do.... "I always just run whatever the manual says"
as for the weight: Higher temp areas will probably benefit from 5w-30 or higher.
here's the problem with your scenario
- There is no way to tell whether switching to Synthetic at this point will make a difference. If we cloned your motor, installed it in another RX8 and ran that with non-synthetic under the exact same conditions as your current motor being switched to Synthetic only then could we have a side by side comparison.
What is your compression now?
I ask because what if it's already low, you switch to synthetic and then your motor fails in 10,000 miles.
Will you blame the change in motor oil? Maybe and that failure most likely was not caused by the oil but rather an engine that was already losing compression.
Your motor might be running "trouble free" right now but that isn't always the best indicator of compression. Ask me, I know.
My motor runs like a CHAMP, has consistently been one of THE highest whp motors at every dyno day I host (I've dyno'd hundreds of 8's over the years) and yet I know for a fact that my rear rotor is below the acceptable tolerance and my front rotor had 1 face failing and the other 2 are within 2 psi of failing.
Oh, and those compression results are over 18 months old and my car still runs like a beast yet I would venture to guess that over that time my compression has continued to drop.
Not bragging at all, simply sharing my experience that how a car 'feels' isn't always the greatest indicator of engine health.
You're right, dealers can't tell if you run synthetic or a different weight oil. My advice to people, "STFU and don't volunteer that info if the dealership doesn't ask for it." And if they do.... "I always just run whatever the manual says"
as for the weight: Higher temp areas will probably benefit from 5w-30 or higher.
Thread Starter
Rx7 and now Rx8
Joined: Jun 2006
Posts: 142
Likes: 0
From: Tucson, AZ
Well, you've read the stickies, so that's a good starting point. I'll just sum things up.
The reason that this argument exists is because of the OMP - the pump that sends oil to your apex seals. ANY oil that resists breakdown under high temperatures is going to be problematic for use in your car. If your oil doesnt break down when detonated, it will be problematic, so:
Ask your friend how much experience he has running that stuff in 2-stroke motors.
This is why people use the Sohn adapters... The apex seals get clean-burning 2-stroke oil, and the rest of the motor can use whatever synthetic your heart desires.
The reason that this argument exists is because of the OMP - the pump that sends oil to your apex seals. ANY oil that resists breakdown under high temperatures is going to be problematic for use in your car. If your oil doesnt break down when detonated, it will be problematic, so:
Ask your friend how much experience he has running that stuff in 2-stroke motors.
This is why people use the Sohn adapters... The apex seals get clean-burning 2-stroke oil, and the rest of the motor can use whatever synthetic your heart desires.
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