Types of fuel

rmg1

Hi all

I've just noticed that I've been filling up my car with normal unleaded but the sticker just inside the petrol flap says I'm supposed to be using super unleaded.
The car is a Mazda 6 Takyuma (I think I spelled that right).

This may be a stupid question but am I doing the engine any damage?
Obviously, I'll be filling up with the higher-octane stuff in future, but do I actually need to?

TIA

Richard

knightstyle

Probably best to ask on here  http://www.mazda6forums.co.uk/index.php

AdrianC

I'd be very surprised if it really does need 98RON super.

A quick google suggests that the "Takuya" was just a few bits of stick-on on top of a normal mid-spec 2-litre petrol Mazda 6.
https://www.whatcar.com/news/mazda-launches-takuya-special-editions/n6800

rmg1

Thanks folks, I'll head on over to the Mazda forum.

eamon

Anything in the owners manual?

jimbo6977

Could this be to do with the octane ratings of fuel in Japan? They go from 90 to 96 as opposed to 95 to 97/8/9 in Europe.

Or could it be that in some places in Europe, 95 is called "super" even though it's very ordinary?

The_Fat_Controller

Go by what is in the manual.

AdrianC

jimbo6977 said:

Could this be to do with the octane ratings of fuel in Japan? They go from 90 to 96 as opposed to 95 to 97/8/9 in Europe.

Why would a UK-spec car have a Japanese octane sticker... in English?

Anyway, Japan uses RON, same as the entire world except for the US - which uses the lower AKI or RON+MON/2 - is what you're probably thinking of.

Or could it be that in some places in Europe, 95 is called "super" even though it's very ordinary?

No - the description is part of what's standardised description across the continent (yes, including this little damp lump of rock off the north coast).
95 is Premium, 97/8 is Super.
91 was "regular", but that never really caught on, and hasn't been widely available since the 90s.

RobM99

If you're using a fuel that's 3 numbers (Octane) lower, the car would 'pink' at low rev's and under strain (going uphill, accelerating) as the compression ratio will not be high enough, the fuel will burn by compression rather than the spark, like Diesel. (That's why Diesel engines don't have spark plugs).
But as mentioned, go by the manual. Premium is 95 octane minimum, the test has a 0.3 tolerance anyway - so at the pump it should be at least 95.3.    How about using Premium (if that's what the manual says) and using a dash of Super?   Won't make any difference but peace of mind counts here!

AdrianC

RobM99 said:

If you're using a fuel that's 3 numbers (Octane) lower, the car would 'pink' at low rev's and under strain (going uphill, accelerating) as the compression ratio will not be high enough

Umm, yes - and very no.

Higher compression ratios are more likely to lead to pre-ignition/pinking. But any UK market non-performance car that's set up for 98 should certainly have a knock sensor to retard the ignition when run on 95.

Philipp_Bach

If you used 95 instead of 98 it will not harm your engine. But you should know, that it is not recommended to do this often. As an exception - it is no problem.
Lower octane fuel can have impact on transmission parameters, if she is pre-selective (adaptive), and you can feel more discomfort when shifting. And this is only one of the episodes of how the unproper fuel impacts your car.