Super unleaded - is it worth the extra cost?

[funkyrobot]

I changed from a diesel car to a petrol one in September and am now used to the green pump. Now that I take notice of this colour of pump, i've wondered whether or not I should invest in the other green pump, the super unleaded one.

I have a 57 plate Mazda 3 sport which states on the filler cap 'unleaded, minimum 95 ron', which is obviously the standard unleaded. But i've been wondering whether I really should be using the higher octane fuel?

So, is it worth me using super from now on? And what are the benefits? I've heard that the fuel burns better so you get better consumption, and the car performs slightly better, but are these claims true?

Thanks all.

[funkyrobot]

matchmaker said:

You have stirred up a hornets nest here..........I can only speak for my own car, an Octavia vRS. In the handbook and in the filler cap 98 RON is recommended. I run it on Tesco 99 RON. If I use 95 RON I notice a loss of power and worse fuel consumption.

st. Sorry. Don't want this to turn into a fuel slagging match. I just wondered if it would make a difference to my car. Maybe I should investigate further myself.

[funkyrobot]

Thanks all. I'll double check my handbook. The fuel flap (mentioned above) says min 95 RON to maybe I should just stick to this.

[funkyrobot]

pilchardthecat said:

john_p said:

pilchardthecat said:

It's about 7p/l (5-6%) more expensive, but i get maybe an extra 20 miles out of a 50l tank (which is about 7%) so they both cost the same, pretty much

My car is happy on 95, but you can notice the difference in power delivery between 5k and 8k rpm (s54b32 engine)

That engine is DESIGNED to run on 97/98 ron

Using 95 is possible, but with reduced power and efficiency. I'm pretty sure it says that in the manual. You're not getting 'extra' miles, you're getting less when you use 95.

That sounds like you're saying exactly the same thing as me in a slightly different way.

Cost wise, there is very little in it... that was my point.

Sorry to sound daft, but do I need to do anything else other than look in the manual to find out my engine type? I've checked the book before to find out the engine for the oil type, but can't remember it off the top of my head.

Thanks.

[funkyrobot]

Right, just checked my handbook. For the turbocharged L3 engine (which I think is the Mazda 3 MPS one) they recommend 98 ron. You can use 95 ron in these cars though according to the book.

My 2.0i Sport model seems to fall under the 'every other petrol engine' section which is below the turbo engine section. This simply says '95 ron or above'. Therefore, i'm guessing 95 is fine but I can use higher octanes if desired?

Thanks.

[funkyrobot]

AJB said:

funkyrobot said:

Right, just checked my handbook. For the turbocharged L3 engine (which I think is the Mazda 3 MPS one) they recommend 98 ron. You can use 95 ron in these cars though according to the book.

My 2.0i Sport model seems to fall under the 'every other petrol engine' section which is below the turbo engine section. This simply says '95 ron or above'. Therefore, i'm guessing 95 is fine but I can use higher octanes if desired?

Exactly right. So the turbocharged one is optimised for 98 ron. It can cope with 95 but only by reducing economy and power in the process, so probably not saving any money overall and definitely losing performance.

Yours is optimised for 95 ron. Using 98 might very slightly increase power/economy (if it's got a knock sensor) - but only very slightly, and not certainly not justifying the extra cost of the fuel on financial grounds. Or using 98 might very slightly reduce power/economy (because the 98 ron fuel has got slightly less energy in it).

For either engine, you won't do any harm at all by using higher ron fuel than specified (other than to your wallet).

Thanks AJ.

I think i'll take a look at putting in a tank of super every now and again to try and make use of the cleaning additives. I'll also run a tank of it to see if it does make any difference

Edited by funkyrobot on Wednesday 22 December 09:03