VR4 petrol do I use 91 or 95

[deacolanza]

Hi just a quick question, I have owned a VR4 for about 2 weeks now and the previous owner used 91 petrol in it. But was wondering if the car would perform better if I used 95 unleaded.
Thanks for your help.

[mattnz]

98 is all mine gets, if it's been run on 91 for a long time, there's gonna be a bit of acid bathing for you to do.

[Ryan]

Hi just a quick question, I have owned a VR4 for about 2 weeks now and the previous owner used 91 petrol in it. But was wondering if the car would perform better if I used 95 unleaded.
Thanks for your help.

91 is a no-no! 95 is okay if you plan on keeping it stock boost pressure, 98 for anything else. When you fill up with 95 or 98 it may pay to reset your ECU by disconnecting the battery for a minute.

[bradc]

Indeed, it is actually designed for 100 octane, so you need to run the best you can buy which is 98

[deacolanza]

Thanks for that, i'll try 95 as I haven't seen 98 anywhere around.

[giblet]

To quote the sticker on the inside of my petrol flap -

[Turbo_Steve]

NZ use MON and not RON, though, so it's a tad more complex.

[Nutter_John]

95 mon is roughly 98 /99 ron , so if 98 mon is the top fuel in nz then that will be 101/102 ron , which would explain the high numbers achived on dynos

[Kelly&Ben]

95 mon is roughly 98 /99 ron , so if 98 mon is the top fuel in nz then that will be 101/102 ron , which would explain the high numbers achived on dynos

very interesting!

[John TheAntique]

Afer all these years NJ's cracked it.

[aboo]

Was thinking the same John.

[bradc]

No, we use RON

http://www.shell.com.cn/home/content...l_changes.html

In New Zealand, petrol is unleaded, and most commonly available in 91 RON ("Regular") and 95 RON ("Premium"). 98 RON is available at selected BP ("Ultimate") and Mobil ("Synergy 8000") service stations instead of the standard 95 RON. 96 RON was replaced by 95 RON, and subsequently abolished in 2006. Leaded fuel was abolished in 1996.

http://www.dave.net.nz/drupal-4.7.2/?q=node/26

http://www.med.govt.nz/templates/Mul...____10382.aspx

[Nick Mann]

Our lowest grade is 95 - also called Premium. We don't get Regular.

As for the original question, I wouldn't ever recommend 95 ron. Plug in Evoscan and go for a run - your car will show a MUCH higher knock count on 95 RON than 98. Usually enough for the ECU to start pulling timing, and this is a cumulative effect, so driving aggressively for a couple of minutes will cause significant knock and a huge loss in power.

Super unleaded at every opportunity - if you have no choice, then use premium and drive like a granny until you get super back in it again.

[Ryan]

NZ use MON and not RON, though, so it's a tad more complex.

No we don't.

[Ryan]

As for the original question, I wouldn't ever recommend 95 ron. Plug in Evoscan and go for a run - your car will show a MUCH higher knock count on 95 RON than 98. Usually enough for the ECU to start pulling timing, and this is a cumulative effect, so driving aggressively for a couple of minutes will cause significant knock and a huge loss in power.

I respectfully disagree. On standard boost settings Brad and I have used EvoScan to log the knock count and IIRC while there was indeed some knock, it wasn't alarmingly high.

Some NZ members (KiwiTT I believe) use 95 in the standard boost application.

Whilst I'm not advocating the use of this grade of petrol, I don't think it's a train smash to do so if your car is on standard boost.

[Turbo_Steve]

Oops! I even think we've had this conversation before.

I've had a variety of experiences with cars that have been exported and come back failed, or exported and I've seen the results of subsequent remaps, and the differences in timing have surprised me!

95Ron out there is definitely less knocky.

[Nick Mann]

Could well be a country thing then? Maybe in NZ standards are tougher on petrol ratings?

All I know is that the few VR4s I have run evoscan on that were burning 95 in the UK have shown knock counts well in to the teens. Timing was pulled substantially and the ECU RON rating was knocked back to the 80s. I'm sure that had we carried on giving beans, the octane level would have dropped further. The same cars running 98 showed knock counts of 2/3 under the same conditions.

[John TheAntique]

Damn. Thought there was a Eureka moment there. Sorry John.

[Nutter_John]

Yeah maybe we should just face facts all mappers in the world are inferior to the NZ ones

[John TheAntique]

It's not just the mappers, it's the drivers as well, exceptional skills down under.