Optimax RON going down??

[OLLY-B]

I was chatting with Top Cats Racing and they said that in the last 6 months they have seen a marked increase in Tivs coming in with pinking issues (these are regular clients with 'known' engines so an outside factor is indicated.)

It raised the possibility of premium fuel brands subbtly dropping the RON now that everyone is used to buying it regularly??

How many of you have a feeling that your Tiv is a bit more 'pinky' than it used to be?

I know mine is

It is all subjective I know but.....

[groucho]

Mine pinked last year on a really hot day. I was told that opti "goes off" quickly.

>> Edited by groucho on Friday 1st July 17:38

[bosscerbera]

I'm pretty sure the rumour that tankers 'accidentally' chuck 95 in the 97/Optimax tanks has a basis in truth.

My 5.0 AJP is very sensitive to octane rating and some days its sparkle is missing and it pinks.

Is it possible to test octane rating at home with a simple test of some sort? Any chemists out there?

[cerber450]

Probably just the ambient air temperatures are higher at this time of year. We run less boost in some turbo cars through the summer as they pink and then turn it back up in the winter.

[valhalla]

How many of you have a feeling that your Tiv is a bit more 'pinky' than it used to be?

I know mine is

It is all subjective I know but.....[/quote]

Funny you should say that!! coz i have been wondering why my T350 has started pinking again, I thought that it was because i have been using Ultimate, but it still does it with Optimax.
If they are dropping the Ron number, then perhaps they should drop the price(IMHO)
Dave

[crankedup]

I thought that RON was covered by law, like buy a Kg of jam and it must be that. So the RON should be stated on the pump and thats what your buying, if your sold short then surely an offence has been commited??

[gavmitchell]

We are running Sunoco 102 octane in the championship we currently race in. Mix this with some Millers CVL Turbo and you have a 105 octane brew. Put this mixture in a Chim 5.0 and it goes like it's on acid.

[mwtryan]

I'm running a T350C in SA at extreme high altitude - also our fuel is only 93 Octane - to help with this I use an octane boosting additive (takes the rating upto 96) but car always "knocks" on warm start-up and occasionally pinks under stress. The only Tuscan S sold in SA actually destroyed itself recently due to "detonation". I think the only way to ensure that your octane is right is to use the booster (we have no choice over here) however it does make running the car an expensive business.

[OLLY-B]

crankedup said:

I thought that RON was covered by law, like buy a Kg of jam and it must be that. So the RON should be stated on the pump and thats what your buying, if your sold short then surely an offence has been commited??

You right in a way. It must be a MINIMUM RON. Rumour had it that when launced Optimax was sometimes as high as 102 RON. Therefore if your engine was retarded to avoid detonation on 102 Ron and it later drops to 97 Ron then it's possible that the pinking returns.

[grahamw48]

Hmm.

My 390SE started pinking (for the first time in my ownership) last week, after I topped up with a few gallons of BP Ultimate.

I later topped up with Optimax - still pinking, and then put in a bottle of STP octane booster - still pinking!

Nothing has been touched on the engine, for at least the past month.

The head scratching starts.

[Esprit]

In NZ we have 2 grades of fuel: 91 and 96 with 98 available as "BP Ultimate" and "Mobil Synergy 8000" at selected locations. My Lotus should be fine on 95 or above so it HAS been running 96 fine... but I've noticed that about 50% of times after filling up it pinks... I run 98 and never have any issues... I think that frewuently the "number" they attach to it isn't RON, it's just some marketing octane number they attach to it. I only ever use it as a yardstick and ALWAYS leave myself some leeway for the apparent variablility in its quality.

Independent tests have shown in the past that in NZ some 96=93 and 91=89! It's not like this all the time but on occasions the levels can drop!

[z_chromozone]

cerber450 said:

Probably just the ambient air temperatures are higher at this time of year. We run less boost in some turbo cars through the summer as they pink and then turn it back up in the winter.

Also, changes in humidity play a small part. Less water / cooling = more det', try driving your cars at 5 in the morning on a nice cool summers day and see how well they go.

Z

[keithyboy]

Filled up at Tesco Sunday with their super-unleaded - pump marked "99" the S loved it

[DavHughes]

My Chimaera started minor pinking the other day. Was using Shell Optimax. Recently changed to BP and she's running better - but it could be due to the weather getting cooler I guess.

Love to talk - but I'm off to Tescos!

Dav