Me again. I’m annoying huh. Anyway, I’ve always used 95 or 98 fuel for my last few cars, they’ve mostly been euros. Hubby has usually had the diesel car so I’ve managed to avoid the heated discussion it brings. Until now. He has a Jeep Wrangler and has been putting 95 in but apparently today googled and American fuel is 87 and their premium is 91. So he’s arguing that he should use 91 cause it’s the American equivalent of premium. I actually have no comeback, is he right?
In Europe(and here), the octane rating on the pump is simply the RON figure. America, by contrast, uses the average of the RON and the MON figures, called the AKI (anti-knock index). Thus, 97 octane “super unleaded” in Britain is roughly equivalent to 91 octane premium in the United States. https://www.economist.com/babbage/2012/09/17/difference-engine-who-needs-premium
Another site says - Pump gas
In the United States gas stations describe the types of gasoline based on the Pump Octane Number (PON). That number is the average between RON and MON. This causes many problems.
If a fuel is 98 RON then it will be 93 PON -> 93 PUMP If a fuel is 95 RON and 87 MON then it will be 91 PON -> 91 PUMP
So no for our 91, not unless he wants to kill it.
intrade,
Oct 12, 8:04pm
ron and mon different rating system different proppertys mesured. But basically no car can run on 91 catpi$$ its a bit like running it on 91 5 years from new and come here and claim nothing wrong and selling it to buy a new car and the next guy buys the bomb thats about to go off in repair bills.
serf407,
Oct 12, 8:46pm
Also to remember that some remote area pumps in NZ only have NZ 91 octane petrol available so take some octane boosters with you if visiting those places and calculate you will need a fill up.
lythande1,
Oct 12, 9:29pm
You use what the car manufacturer says to use.
framtech,
Oct 12, 9:36pm
The issue is not killing the motor, its the fact that the engine will be altering the ignition timing to stop it pinking and therefore its performance will be crap. some cars are designed to handle our 91 but most euro and american cars are not turned for our crappy fuel.
irishdymonz,
Oct 12, 9:46pm
I disagree. The manufacturer said I should use 91 in my Mitsubishi and it ran like crap until I used 95. I now have a Mazda and the dealer said the recommendation was that I use 91, but he believed it was best run on 95. I’ve taken him at his word. My husband runs his Corvette on 98 when he can get it, otherwise 95. He’d never run that on 91.
gpg58,
Oct 12, 10:10pm
Basically agree, would never use 91 in ANYTHING at all. Most cars say use a minimum of 91, that does not mean do not use a higher rating, least i have never seen one say use a maximum of.
But a few times over the years, i have posted my belief, that most cars run cheaper when worked out on kilometers per dollar, on the highest octane available(as i had proven to myself many times).
But my current Holden spark(2020) seems to be an exception, i have tried 3 tanks on 98, with 95 between each, and have to admit that on the results, it looks like i actually get more km's per tank on 95, without even taking the extra cost of 98 into account, or any noticeable power difference. (still trialing the 2020 astra rsv, but does so far seem to go further per tank on 98).
franc123,
Oct 12, 10:37pm
No definitely not right the Yanks calculate the ratings differently as per #4. Unless the manufacturer specifies 98 or higher (a very small % of cars), our 95 is the best fuel to use in ANYTHING.
alowishes,
Oct 13, 8:57am
Old school V8s I have go best on 98, even better on 100 when I can get it (At NPD) 95 is sort of OK as long as I have a light foot on the accelerator, otherwise it’s ping city.
bwg11,
Oct 13, 9:07am
Possibly your 'old school V8', is trying to tell you something about your static timing or advance curve?
nice_lady,
Oct 13, 9:49am
Old school V8's love Avgas 😁
franc123,
Oct 13, 10:21am
Depends on what it is, if its had compression ratio increases then of course the highest grade is going to be better. We are talking standard unmodified stuff here.
alowishes,
Nov 7, 4:56pm
High comp. But why reduce the timing and lose power and economy just so I can use cheaper low octane fuel?
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