Mazda Rotary Club

General => General Technical => Topic started by: neutroncore on October 15, 2008, 06:18:31 PM

Title: Best oil to use? 5w-20 or 5w-30?
Post by: neutroncore on October 15, 2008, 06:18:31 PM
Hi there,

I have read recommendations that 5w-20 oil be used in an RX-7 - mine is a 1995 model.

I got my local garage to check the Comma Oil database, and this recommends 5w-30 for the RX-7.

What do others use / recommend, is 5w-30 ok?

Thanks

Robin
Title: Best oil to use? 5w-20 or 5w-30?
Post by: NurburgRob on October 15, 2008, 07:58:25 PM
If I get the oil changed at a Mazda Garage they use the RX-8 oil which is 5-30, I also use a 5-30 mineral oil as top up
Title: Best oil to use? 5w-20 or 5w-30?
Post by: neutroncore on October 15, 2008, 10:17:01 PM
Thanks - if it\'s had 5w-20 in it already, should I drain the remaining oil and do a fill with the 5w-30, or can you top up with a different oil?

Oil is lowish anyway (and I don\'t intend to let it get anywhere near low again).
Title: Best oil to use? 5w-20 or 5w-30?
Post by: m1tch on October 15, 2008, 10:23:25 PM
Probably best to just swap oils over, regular oil changes are good :)
Title: Best oil to use? 5w-20 or 5w-30?
Post by: RedRummy on October 16, 2008, 01:21:55 PM
I use 10-40w mineral in mine.
Title: Best oil to use? 5w-20 or 5w-30?
Post by: neil_jdmr on October 16, 2008, 03:53:37 PM
Ive always used 10/40 halfords mineral oil in mine
Title: Best oil to use? 5w-20 or 5w-30?
Post by: RedRummy on October 16, 2008, 07:46:16 PM
yep thats the one
Title: Best oil to use? 5w-20 or 5w-30?
Post by: NurburgRob on October 16, 2008, 08:13:50 PM
Sorry, my Top Up is infact Halfrauds 10W 40 Mineral.

Topping it up won\'t kill it mate but might aswell get the lot changed and filter too :)
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on October 16, 2008, 08:32:23 PM
dont need to change oil for the sake of it....thats for piston engines
Title: Best oil to use? 5w-20 or 5w-30?
Post by: RedRummy on October 17, 2008, 10:37:10 AM
FD oil gets prett black pretty quickly... the old wankel burns oil pretty good.
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on October 18, 2008, 12:07:20 PM
Quote from: RedRummy;545454FD oil gets prett black pretty quickly... the old wankel burns oil pretty good.

the oil goes black very quickly because it burns, this happens on turbo motors {temperature} -there is
nothing really wrong with the oil at this at this stage it still does its job; over time the
oil molecules sheer and effectively no longer provide the protection {think thats tech acurate}

There is a nice long tech speel on oil in this forum that describes the diff oil types etc etc...

I myself have been to reworx and the question asked is not so much "is the oil black" but WHEN LAST WAS IT CHANGED, and what has the FD been doing all this time...
Factors here are whether its mineral or syn, has it turned to sludge.....etc etc


Amen
Title: Best oil to use? 5w-20 or 5w-30?
Post by: joshrulz on October 18, 2008, 12:23:50 PM
http://www.ausrotary.com/viewtopic.php?f=16&t=263
Title: Best oil to use? 5w-20 or 5w-30?
Post by: neutroncore on October 19, 2008, 04:44:31 PM
Thanks guys
Title: Best oil to use? 5w-20 or 5w-30?
Post by: dj_dee99 on October 19, 2008, 06:25:03 PM
Castrol GTX 10w40 mineral all the way for me.
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on October 23, 2008, 03:32:17 PM
1. Mazda can test & approve oils till the year 2200, all they care about is the motor and its seals -when
last did you take the OEM\'s word for it,
Their motive is to make money and get you buying OEM parts and £70 per hour to change light bulbs...

2. mineral oil doesn\'t provide the protection for the turbo especially at high rpm / high performance and
thats what we do isn\'t it !? -modifying and replacing OEM....
..thats why we have synthetics and semi-synthetics....
Title: Best oil to use? 5w-20 or 5w-30?
Post by: Jimi_Hendrix on October 23, 2008, 05:53:11 PM
I\'ve just done an oil and filter change and i used Castrol Magnatec 5W-30. Its semi synthetic so i think it\'ll be fine.
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on March 03, 2009, 11:07:29 PM
...it sure is hard to find mineral oil these days.....
Title: Best oil to use? 5w-20 or 5w-30?
Post by: SmbFD3S on March 04, 2009, 06:39:39 AM
There are lots of opinions on oil and everyone will have a different view mate, it\'s been done to death on here if you do a search and no-one will give you a definitive answer lol.
 
 
I\'ve always used Comma Xtech 5-30 in mine and it\'s been used in the car for 11 years as i have all the service record.
 
Just dont mix mineral and Synth oils, they dont mix...
Title: Best oil to use? 5w-20 or 5w-30?
Post by: Jim_rx7 on March 04, 2009, 09:55:51 AM
10/40 mineral oil here
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on March 04, 2009, 08:18:12 PM
Quote from: Jim_rx7;58877710/40 mineral oil here

..ok, point is its not as freely available if you want to buy it....last time I walked into Halfords
their shelves were stocked up with the "halfords semi synthetic"....
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on March 04, 2009, 08:20:44 PM
Quote from: SmbFD3S;588753There are lots of opinions on oil and everyone will have a different view mate, it\'s been done to death on here if you do a search and no-one will give you a definitive answer lol.
 
 
I\'ve always used Comma Xtech 5-30 in mine and it\'s been used in the car for 11 years as i have all the service record.
 
Just dont mix mineral and Synth oils, they dont mix...

i\'m not arguing "which oil to use"....you can read the tech stickie yourself and decide what to
use...you\'ve got the wrong end of the stick..
you don\'t need to tell me not to mix synthetic + mineral...
Title: Best oil to use? 5w-20 or 5w-30?
Post by: ashc on March 04, 2009, 09:18:30 PM
castrol gtx 10/40 mineral in mine for the last 2 years no probs so far !
Title: Best oil to use? 5w-20 or 5w-30?
Post by: Jim_rx7 on March 04, 2009, 09:21:43 PM
Halfords should always stock the 10/40 mineral mate... I work there
Title: Best oil to use? 5w-20 or 5w-30?
Post by: rx7_bhp500 on March 04, 2009, 09:30:58 PM
Quote from: Jim_rx7;588960Halfords should always stock the 10/40 mineral mate... I work there

didnt see any at the time, otherwise I would have bought it....99% of the motorway services
don\'t stock mineral neither since I\'m on the road a lot these days -pretty fed up; as you can tell its a hot topic and opinions and opinions...hence mineral is my safe bet blah blah...driving
it like an OAP so don\'t need no £60 per litre extra special semi-synthetic.....
I\'ll pick up / try out the catrol gtx if I can find it...
I won\'t use any of that foreign Q8/oil brands I never heard of before...

Amen