Viper fuel

[Dundiggin]

HEY THERE YANKS.
I,M IN AUSTRALIA WITH A 2002 GTS VIPER. FUEL CAP SAYS ''91 PREMIUM UNLEADED FUEL ONLY.
91 OCTANE IN AUST IS STANDARD UNLEADED PETROL. PREMIUM UNLEADED IS...98 OCTANE. WHICH ONE FOR MY VIPER?
REGARDS Dunduggin.

[Viper98]

Howdy Dundiggin. Looks like you joined two days ago. Welcome aboard, mate!
Others will chime in, but it depends on what you are going to do with the car: street, strip, autox. If just street 91 is fine. If racing a higher octane is better.

Got any pics?

[RedTanRT/10]

HEY THERE YANKS.
I,M IN AUSTRALIA WITH A 2002 GTS VIPER. FUEL CAP SAYS ''91 PREMIUM UNLEADED FUEL ONLY.
91 OCTANE IN AUST IS STANDARD UNLEADED PETROL. PREMIUM UNLEADED IS...98 OCTANE. WHICH ONE FOR MY VIPER?
REGARDS Dunduggin.

Fuel in the US and Canada has a lower numerical value than fuel in Europe and Australia

It has to do with differences in the rating methods

US/Canada 91 would be equal to 96 or 97 in Australia. Do a quick Google search

You should us the Australian 98 octane. Good luck, Mike

[ViperTim]

A quick research shows that Australia uses RON like Europe.
So MON 91 (US) would therefor be RON 95 (Australia/Europe etc.).

With that being said, I use RON 98 in mine just for the sake of it.
But I know plenty of people running RON 95 without a single issue at all, and none of those cars are trailer queens. They are driven hard.

Honestly, you could most likely run RON 93 or even less in these engines. It's not like they're fine machined piece of engineering.
They're 8.0L beasts making "only" 450hp....

[dave6666]

Octane is a rating of how resistant the fuel is to precombustion. Not how much power it makes regardless of other parameters. An engine tuned for 91 may not see any performance gain from 93. Although not all detonation can be heard, if you don't hear any you are probably okay. If you have gotten the car tuned to a specific octane you should run that octane always.

[GTS Dean]

In the US, our fuels are rated as an average of Road and Motor octane values using the formula (R+M)/2.

[ViperSRT]

In the US, our fuels are rated as an average of Road and Motor octane values using the formula (R+M)/2.

Research and Motor

[Dundiggin]

Thank you all for the info.It's been very confusing. Been asking on line for months. I have had my vehicle since Oct,only driven it 2 or 3 times.The engine light kept coming on.
put a scanner on it and found it was low on air conditioner gas.I think if i farted in this car it would throw up a light!! New battery has helped . Now with no warning lights coming on, i can go and enjoy a drive.Thank you all for the information.

regards ROBBO.