Oil - correct type and consumption

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Oil - correct type and consumption

Post by Naz » Tue Jan 18, 2011 1:16 pm

There are various reports about stupendously high oil consumption for the RX8. This is a myth. It does not use any more oil than any other sports car does. In fact the benefit is that it doesn’t use the expensive stuff. With discounts through the club you can usually get about 4 litres for about £25.

Oil consumption will be around 500ml for every 1,000 miles. But keep in mind that the harder you drive the more it will use. It is best to check your oil on every second fuel fill up until you get an idea of how much you are using.

Correct oil is 5w-30 semi-synthetic. In fact semi-synthetic, synthetic blend and part-synthetic all mean the same thing. However, DO NOT USE FULLY SYNTHETIC. Many members on the club use Fuchs Titan XTR 5w-30, as well as the Mazda recommended Dexelia.

The scale on the dipstick is non-linear due to the shape of the sump.
This is what the dots mean. A US Quart is just under 1L
Image

More questions on oil are answered here http://www.rx8ownersclub.co.uk/forum/vi ... =29&t=3711
Last edited by Naz on Sat Aug 27, 2011 5:26 pm, edited 2 times in total.
Reason: Added dipstick diagram
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Re: Oil - correct type and consumption

Post by warpc0il » Wed Mar 02, 2011 2:27 pm

Engine Oil Capacity
  • Oil replacement 3.3L
    Oil and filter replacement 3.5L
    Engine holds 4.7L
    Engine fitted with single cooler 5.8L
    Engine fitted with twin coolers 6.7L (All EU Models)
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Re: Oil - correct type and consumption

Post by warpc0il » Wed Mar 23, 2011 11:15 pm

Engine flush isn't recommended for the Renesis for three reasons;
- chemicals in engine flush damage the rotor side seals.
- oil is injected into the compression chambers but engine flush isn't designed to burn.
- the engine and coolers hold 6.7L but only 3.5L get changed each time, so the flush doesn't come out on the next change.
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Re: Oil - correct type and consumption

Post by warpc0il » Tue Mar 27, 2012 6:44 pm

Mazda (Japan) published the Service Schedule before Mazda (UK) decided to specify dual oil coolers as standard for UK models - for marketing rather than engineering reasons

Adding the coolers not only increases the total volume of the engine oil but it also means that only ~50% of the oil is drained and therefore replaced at each oil change.

This is why you should change the oil at a minimum of 6k miles or 6 month intervals.

[urlw=http://www.rx8ownersclub.co.uk/forum/vi ... 88&start=1]See here for more details[/urlw]
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Re: Oil - correct type and consumption

Post by Naz » Wed May 16, 2012 9:57 am

Some more info on oil and the choices available

The TYPE of oil recommended by Mazda is 5w-30 ACEA A5 (A5 overlaps A1 & A3 - original recommendation in 2003 was to use A1 or A3, changed to A5 a couple of years after as A5 is a more recent classification) processed (hydrocracked) mineral oil, that are legally able to be branded as synthetic in the UK and many other countries. Not ester of PAO based synthetics.

The BRANDs of oil that fit this are numerous, and include:

Mazda Dexelia 5w-30 (made by Total). Recommended by Mazda.
Motul 8100 Ecoenergy 5w-30. Recommended by Opie Oils, used by some members, including myself for past 5 years.
Fuchs XTR 5w-30. Recommended by Fuchs, Opies Oils and numerous members.
Castrol Magnatec A1 5w-30. Recommended by Castrol, used by many members. Is in fact an A5 nowadays rather than A1, despite the name.
Halfords 5w-30 part-synthetic. Made by Comma.
Millers XSS 5w-30.
Mobil Super FE 5w-30
Total quartz 9000 5w-30. Same manufacturer and spec as Dexelia.
Comma Xtech 5w-30. Comma provided written assurance on this for RX8 a few years back. Now upgraded to A5.

Some may suggest other oil types and grades not recommended by Mazda, and that is for users to take an educated view on.

The Mazda handbook creates confusion, as Dexelia is claimed by Total to be based on "advanced synthetic oil technology"
http://www.total.be/be/content/NT0000C5F6.pdf
So questions like this are bound to come up time and time again.
The confusion is answered by the legality of branding processed mineral oil as synthetic in the UK and other markets.

(Thanks to Lucky7 for this info)
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Re: Oil - correct type and consumption

Post by warpc0il » Fri Aug 17, 2012 1:13 pm

Most of the independent Mazda specialists now recommend the use of 10W40 mineral oil rather than 5W30, some even require the use of 10W40 as part of their warranty on rebuilt engines.

All Mazda rotary engines before the RX-8 Renesis has specified 10W40 and the main bearings and many other components that require protection from the oil are common between the Renesis and the later RX-7s.

It is believed that Mazda switched to the thinner 5W30 oil in an attempt to improve fuel consumption, at they did across all their car range, though there is no evidence that this is effective on rotary engines.

There is however growing evidence that bearing failure is much more common on Renesis engines that have been run on 5W30, than on pre-Renesis engines or Renesis engines running on 10W40.

While the Owner's Club does not make any official statement against the Mazda recommendation, I can confirm that I have been using 10W40 in my car since I got it and many well respected members have made the same personal choice.

Further reading on the subject is available by [urlw=http://www.rx8ownersclub.co.uk/forum/se ... mit=Search]Searching 10W40[/urlw]; note that forum guests will not see threads within the Member's Only areas.

These particular threads are relevant;
[urlw=http://www.rx8ownersclub.co.uk/forum/vi ... =6&t=40903]10W40 or 5W30?[/urlw]
[urlw=http://www.rx8ownersclub.co.uk/forum/vi ... =6&t=40903]What oil do you use??[/urlw]
[urlw=http://www.rx8ownersclub.co.uk/forum/vi ... 30&t=45180]Stationary Gear bearings[/urlw]
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Re: Oil - correct type and consumption

Post by warpc0il » Wed Aug 29, 2012 12:59 pm

When changing the oil, you need to prime the new filter by filling it with clean oil and let it stand somewhere warm for at least 10 minutes, for the oil to totally saturate the element.

Wipe oil around the seal then pour out a little so that you don't spill much as you, very quickly, invert it and screw in place.

Only tighten by hand and don't be tempted to use any tool (e.g. socket on the nut-bit of K&N filter), that's only there for removal.

If you were to fit a filter dry, the engine doesn't get any lubrication until the filter fills up, by which time a lot of damage could have occurred.
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