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Super Unleaded

Does anyone use super unleaded (97Ron) I tried it for the first time the other day. At first (40 mile) it made the engine very loud and it didnt run very well, but now it seems alot better

What are everyone elses opinions of it?

i was told "Super unleaded 97Ron" was an Optimaxs equivalent?! just another brand name. i never notice any change in performance no matter if i use std unleaded / Optimax / super unleaded. Its all in the mind if you ask me.
  Skoda Fabia vRS

optimax is 98 ron iirc, and also has cleaning additives, so its not exactly the same as super, but very similar really...

I use Optimax when I can but there is only one shell garage near me so otherwise I use 97Ron Super unleaded from one place to another.

I dont notice any difference between really - I am sure its all in the mind too!! - Car manual recommends 98 Ron
  Nissan R35 GT-R

Its not my favorite. I think you can do better. I have researched a great deal into it and I go for super plus every time now.

Apparently Optimax is actually closer to 99 RON and this the best you can by from your regular garage. Remember reading about a rolling road test once and the max bhp was produced when using Optimax

Theres been huge threads about this, 172s only produce max power with it so im not sure about youre research frosty! My car has a better top speed with optimax my 5mph :)

I never use either Optimax or Super. Doesnt last near half as long because your always putting your foot to the floor to try and see the difference. :confused:

i use 97RON super unleaded, never noticed any gains when i have had to fill up with optimax, so i see no benefits from using it
  Nissan R35 GT-R

Optimax is good if you get through it quickly. It has a tank life and degrades very quickly once reached! It is refined at 98.6 RON (not MON) and degrades after around 40 days. I wont bore you with the deep down technical details, but it does!

In this 40 days it has to go from the refinery into the tanker, and then be transported to where-ever its going, possibly stopping over-night many times on the way.

So it has arrived at the forecourt now. Shell always put it in the smallest tank available as they are aware of the degrading. Now an average Optimax tank is 10,000 litres. This means that if this fuel is not sold quickly it WILL degrade. Even if you get some from the forecourt before its 40-day shelf-life you still have to use it all within the 40-days as well.

RobFenn: There is no way Optimax can improve your top speed. No way in the world.

Im not a technical expert (Except for doing an Automotives degree), but surely more octane = more bhp = slightly (very slightly) higher top speed

  Nissan R35 GT-R

1) My point is that ofter degrading - the Optimax RON rating goes down.

2) More octane doesnt mean more power unless the car has been mapped around it. A car such as RobFenns which has been mapped around 95 RON will not benefit from the extra octane in Optimax.

3) Whether the car makes 75bhp or 300bhp - if the ratio of the last gear is the same and so is the rev limit, the car will go the same speed.

I agree with all those points, but is his car mapped for 95 only, or will it advance the timing for 97 like some cars do?

Plus is the other guys top speed limited by gears or power...? I know mine just wont go any faster due to the lack of power...


I always use the higher octane petrol, although not just because the 16v handbook says to use 95 or 97ron fuel. Higher octane/"Super"/Optimax is always better quality and has more additives.

If I go to great lengths to maintain my car, clean it religiously and am generally very performance-aware, then I make sure Im using a good quality petrol too!

I dont care if its 95 or 97ron, since I hear that knock sensors r****d and advance ignition to compensate for any difference - as long as its good quality Im happy!
  Nissan R35 GT-R

A fair point.

I have never heard of a car that will advance ignition beyond the map settings. I only know of it working the other way i.e. retarding.

Thats probably right, but seeing as I dont know what car he has and what its mapped orignally for, its a bit of a mystery to me... :confused:

I know itd be a waste using it on my car. Would you say, however, that it may be worth using Optimax for the cleaning properties of its additives?

I used to drive for a well known Petroleum company and I can assure you that when the tankers are filled there are different branded tankers carrying exactly the same petrol! Im not saying that there arent different types but dont be fooled by going to one forecourt thinking your buying something totally different from the one up the road.
  Nissan R35 GT-R

The cleaning additives in Optimax have been proven to work. I rate the cleaning properties very highly.

I thought we had concluded that the 172s had an adaptive ECU that will take advantage of the icreased RON rating of Optimax......

Frosty: Interesting what you say about the 40 day life of the fuel.......are you in the industry? I have a tendency to tank it whenever I fill up, but maybe I should go for a "little and often" approach - itll save on weight too!

Busiest Shell I know (hoping that they get fresh stock in all the time) is the one on the South Circular in Ealing.....maybe they should be putting a "best before" date on the side of the pumps....:D