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Cumulative Synthetic Oil Discussion

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Old Jun 15, 2010 | 08:50 AM
  #1251  
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summer RP 5-30 winter RP 5-20.........full syn
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Old Jun 15, 2010 | 11:31 AM
  #1252  
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Originally Posted by realBlackSunshine
summer RP 5-30 winter RP 5-20.........full syn
*sigh*
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Old Jun 15, 2010 | 09:12 PM
  #1253  
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Originally Posted by nycgps
*sigh*
And he's in SC...
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Old Jun 16, 2010 | 02:53 PM
  #1254  
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I agree with the full syn part. Wouldn't have it any other way.
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Old Jun 16, 2010 | 07:38 PM
  #1255  
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SC

Originally Posted by SpIcEz
And he's in SC...
And your point is . . . . ?
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Old Jun 16, 2010 | 08:02 PM
  #1256  
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Temperature difference in SC isn't enough, IMO, to warrant a change in oil viscosity.

Never mind that the differences between 30 and 20 is negligible, especially in SC weather.

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Old Jun 16, 2010 | 08:15 PM
  #1257  
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Originally Posted by SpIcEz
Temperature difference in SC isn't enough, IMO, to warrant a change in oil viscosity.

Never mind that the differences between 30 and 20 is negligible, especially in SC weather.

Good point. Thanks for clarifying!
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Old Jun 16, 2010 | 09:58 PM
  #1258  
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So I read through a lot of this thread (but not all) and ended up getting 10w40 synthetic, thinking the 10 part would be alright since I'm in SoCal. I'm not sure what oil was in the car prior to my changing it, but now it is much more difficult for the car to start. It turns over for perhaps twice as long when cold before firing.

I'm going to guess that this is because 10 is too high, and not because it's synthetic. Is that correct? Given that I intend on tracking my car eventually (which is why I went with 40 instead of 30), do you think I'd be better off with 5w40 or something else? I'm open to suggestion.

Thanks!
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Old Jun 16, 2010 | 10:33 PM
  #1259  
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Originally Posted by stuy486
So I read through a lot of this thread (but not all) and ended up getting 10w40 synthetic, thinking the 10 part would be alright since I'm in SoCal. I'm not sure what oil was in the car prior to my changing it, but now it is much more difficult for the car to start. It turns over for perhaps twice as long when cold before firing.

I'm going to guess that this is because 10 is too high, and not because it's synthetic. Is that correct? Given that I intend on tracking my car eventually (which is why I went with 40 instead of 30), do you think I'd be better off with 5w40 or something else? I'm open to suggestion.

Thanks!
your problem has NOTHING to do with 5/10 oil.

Use your brain and think about it for a second, if your logic is right, Im using 20w50 oil, so that means I need to crank my car for at least 20 seconds before it would start ? \

You have absolutely no idea how oil even works. Go do some homowork first PLUS

Your car has an existing problem. Go fix it.
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Old Jun 16, 2010 | 10:53 PM
  #1260  
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omg
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Old Jun 17, 2010 | 01:13 AM
  #1261  
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Originally Posted by nycgps
your problem has NOTHING to do with 5/10 oil.

Use your brain and think about it for a second, if your logic is right, Im using 20w50 oil, so that means I need to crank my car for at least 20 seconds before it would start ? \

You have absolutely no idea how oil even works. Go do some homowork first PLUS

Your car has an existing problem. Go fix it.
You don't have to be rude about, geez. I never claimed to know anything about how oil works, which is why I am asking you guys, the people who know what you're talking about. I used my brain to notice that as soon as I changed the oil, the car began having difficulty starting, when it didn't before. Please enlighten me, or point me to where I can "do my homework".
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Old Jun 17, 2010 | 01:16 AM
  #1262  
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Originally Posted by stuy486
You don't have to be rude about, geez. I never claimed to know anything about how oil works, which is why I am asking you guys, the people who know what you're talking about. I used my brain to notice that as soon as I changed the oil, the car began having difficulty starting, when it didn't before. Please enlighten me, or point me to where I can "do my homework".
If you were using a factory fill of 5w-20 then a 10w-40 is going to have a greater viscosity when starting a cold engine.

However, the difference should not be enough that would produce problems with the engine starting.

There are plenty of oil threads on this board that will teach you more than you would want to know about oil so I'd say just keep on reading.
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Old Jun 17, 2010 | 02:30 AM
  #1263  
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Originally Posted by nycgps
Use your brain and think about it for a second, if your logic is right, Im using 20w50 oil, so that means I need to crank my car for at least 20 seconds before it would start ?
I said I don't know what kind of oil the previous owner was using, and I never said my car cranks for 10 seconds, so I'm not sure how you came up with those numbers.

I seems like a reasonable conclusion that using thicker oil could cause the engine to crank longer when starting, especially since there was a direct cause and effect (I changed the oil, and it immediately took longer to start). You're probably right, it's likely not the root of the problem, and there's probably something else wrong, but there's really no need to be rude about it, that's all I'm saying.
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Old Jun 17, 2010 | 07:17 AM
  #1264  
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Originally Posted by stuy486
I said I don't know what kind of oil the previous owner was using, and I never said my car cranks for 10 seconds, so I'm not sure how you came up with those numbers.

I seems like a reasonable conclusion that using thicker oil could cause the engine to crank longer when starting, especially since there was a direct cause and effect (I changed the oil, and it immediately took longer to start). You're probably right, it's likely not the root of the problem, and there's probably something else wrong, but there's really no need to be rude about it, that's all I'm saying.
*sigh*

people just never learn.

How about search ? my god.
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Old Jun 17, 2010 | 07:51 AM
  #1265  
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not as much to do with the temp as it does with the fact I rn my car harder and have more track days in the summer, kinda like I run K&N filters in the summer , and puralator gold in the winter..............so not so much to do with weather as it is how I drive the car , but thanx for the input go back to pickin on non-rotar heads........ and for the record I'm from VA and NY sux
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Old Jun 17, 2010 | 07:55 AM
  #1266  
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run K&N in the summer and puralator gold in winter ? ....

I have nothing to say. for real.
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Old Jun 17, 2010 | 08:06 AM
  #1267  
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oh yeah and canadian's are only good for bacon..................LOL, and Exoticspeed, ........let"s not forget that..............I like the bacon better.........LMAO
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Old Jun 17, 2010 | 08:07 AM
  #1268  
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hmmmmmmmmm the better more expensive in the summer and the almost as good but cheaper in the winter..........what don't u understand??

Last edited by realBlackSunshine; Jun 17, 2010 at 08:09 AM.
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Old Jun 17, 2010 | 08:09 AM
  #1269  
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some people own cars and some people know how to treat them and drive them.............. new yorker's know how to flag a taxi..............point proven.....get off my case
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Old Jun 17, 2010 | 10:22 AM
  #1270  
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Some people also love to spread BS.

P.s. I hate nyc taxi
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Old Jun 17, 2010 | 11:46 AM
  #1271  
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^ you mean like saying that you shouldn't use synthetic oil in a rotary! lol
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Old Jun 17, 2010 | 11:56 AM
  #1272  
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Originally Posted by rotarygod
^ you mean like saying that you shouldn't use synthetic oil in a rotary! lol
...

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Old Jun 18, 2010 | 08:31 PM
  #1273  
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Just so that you can have the satisfaction of saying 'I told you so' nycgps, I'm reporting back that my problem was a bad battery, that coincidentally manifested immediately after I changed my oil. New battery, problem gone.
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Old Jun 23, 2010 | 04:53 PM
  #1274  
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Just a quick one for those of you who chatted me about interest in a 30-40w version of Millers heavy duty oil designed for a-series where the gearbox shears the oil - much like the stationary gears in a rotary - although they didn't think there'd be enough demand to warrant making a version for the rx8 lads, they did put me onto some friends of theirs at Motul - regarding using a top quality bike oil instead of the normal car oils.
The advantage there is of course that most bike oils have to lubricate the gearbox too, so they undergo further tests in the form of JASO MA certifications - which ensures the oil is a huge amount more shear stable under heat than most 5w30/40 oils designed for cars.

They recommended their own Motul 300 V 4T Factory Line 5W-30, but said any decent competitors double-ester oil should be perfect - preferably get one designed for Ducati's that run dry clutches as then you gain the benefit of extra friction-reducing additives. (JASO MB specced oils)
However, left field suggestion from the Millers bloke was a 50:50 of their synthetic 5w30 line for the engine oil blended with CRX LS Synth 75w-90 gear oil at the appropriate viscosity...not ideal and a bit suck it and see that one though...especially as it brings you into the high 40's viscosity again...(Silkolene 0w30 with their 70w80 double ester MTF would look a better bet to me, viscosity-wise)

Anyway, next time the motor gets stripped down, the bike oil is going in, and I'll monitor it from there, although we don't really seem to have much of a problem.

Last edited by PhillipM; Jun 23, 2010 at 05:12 PM.
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Old Jun 27, 2010 | 12:33 PM
  #1275  
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hey guys,

I live in Orlando Florida, and it's pretty hot here, with a bit of cold between december / january. I purchased the rx8 4 months ago with 34,000 miles, and the original owner did an oil change before handing over the car, and I currently have 37,000 miles or so on the odo.

I drive my 330i ZHP every once in a while, and the oil changes on that car are pretty much yearly (every 12,000 miles )...and the dealer does the oil changes so i've never really put too much thought into oil; I just drive it an let them service it when it needs to be.

However i drive my 05 rx-8 GT daily for commuting to work and running errands, so i'm doing research on how to maintain this car in the simplest of ways. I work a lot, so I like to keep things simple, and just drive and pay for someone reliable to service it simply so I can get to where I need to be and enjoy the car in my own way. Gas mileage city driving is a steady 250 miles exactly when the orange gas light shows up (I fill up right away), on 18-19 mpg sounds about right to me, no complaints on that...I get the thrill I paid for.

The previous original owner used Mobil 1 Full synthedic 10w40 since he purchased it with 23 miles on the odo back in january 2006 (built date November 2005). I have all the maintenance records, car fax, and everything about this car is flawless; never had any types of failures, recalls, flooding, or anything of that nature...one of the clean ones i guess.

Mostly cruise a 4k on avg; i commute in the city about 30 miles a day...however I do open it up and take it past 6 or 7k rpm for the health of the engine in gears 1 thru 3 every once in a while. The car feels smooth, the idle is smooth, the power is there, everything feels great. I've added 1 quart of Mobil 1 full synthetic 10w40 as the original owner recommended after I checked the oil level 1 month ago.

My driving style is very normal, with a hint of spirited driving during short stretches of open road on the freeway, so I don't dog it out, or track it or anything, just purely enjoying the car, and using it as a daily driver under normal application.

If you would, please recommend the best type of oil suited for my driving style / daily applicaition, vehicle age, location in the U.S (Florida). If mobil 1 10w40 full synthetic will do the job in florida, I have no problem sticking with it.

If non synthetic is the way to go as "Mazda Claims" what's the most reliable choice?

How many of you run Amsoil 0w30 in hot weather states? worth it?

How often does the oil filter need to be changed?

cheers.

Last edited by akagc; Jun 27, 2010 at 12:36 PM.
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