Mk3 Coolant - Generic OAT type or FL22?

My NC(3.5) has just come up for it’s 11 year service which I had done at reputable independent garage near me who’s serviced it for the last few years - but is not an MX5 specialist.

He replaced the coolant, as per the service schedule. However his information database recommended a generic long-life OAT coolant (Red) rather than a specific FL22 coolant. I also noticed if you go onto Halfords (for example) and type in the Reg it also comes up with this type of coolant as an answer. Some stuff I read says that FL22 is just a longer-life version of these modern coolants…

Is it OK to use this and just change more often or should I get it drained/flushed and replaced with FL22. Given the 2.0 engine is (I believe) based on a widely used Ford I’m puzzled why it needs such as specific coolant.

This is my opinion on the subject.

I think the most important thing to remember is not to mix FL22 with any other type, (to be on the safe side).
The reasons being is that the make up/additives may “not be” compatible with each other and could potentially cause issues.
Remember, manufacturers use specific coolant to make sure that it prevents corrosion, and thus debris forming within the system.
Likewise, it is also used to lubricate certain parts and surfaces.

FL22 is as you know is a long life coolant.

Others are and some are not and need to be changed as per the recommendations for that specific coolant.

My understanding is if the coolant “IS FLUSHED” out and other coolant used then you should not encounter any issues.

Personally when mine is due I will use the FL22 no matter what any one else states as that is the Mazda recommended one.

I think you are quite safe to be honest. :+1:

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I used Comma red anti freeze even spoke to Comma technical they confirmed to me it was ok and just the change intervals should be shortened.People who take their cars to a none specialist garage would just ring a motor factors who would supply standard red.

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Thanks @BRUCE225 and @Scarletpimpernel.

Went back and chatted to the garage - he’d double checked with his suppliers and as you say they said it’s compatible but not as long life as the proper FL22. None of the motor factors he deals with stock FL22, so I’ll run it till it needs a change next, then get some FL22 myself.

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Good news and glad to have helped. :+1:

Stick with the red when it needs doing again otherwise you’ll read bad things about old red not drained fully from the engine block mixing with the FL22.Which once again in my mind is a myth because I can’t see garages flushing like myself and others do on this site to make sure it’s a clean change.

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Thanks! Sometimes I wonder if it’s best just not to read too much stuff on the internet!

One of the reasons garages don’t flush is that on a well serviced car and using the original spec fluid there is no need. If you drain and fill the only contamination is previous fluid of the same type. The concentration of the residual original fluid is known (as is the new).
Unless the car has been extremely neglected or contamination has occurred from say a head gasket failure there really is no need to flush.
Ravenol HJC is an easier to source alternative to Mazda FL22 and works out cheaper as concentrated not pre diluted.
Garages using different fluids and making excuses are just being lazy.
All of course IMHO