Hi all, im sure its been asked 100times but what seems to be the best fuel/octane for a standard 998cc mini.. mine being 82
Cheers

I'd imagine an 82 Rover would have an unleaded head so you probably could use std unleaded either 90 or 95 RON. I would not touch anything that has ethanol in it, and obviously 98 octane would be better as it'll give a little bit more kick.

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If the adjust the timing for it.....

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Is your cyl head unleaded? If it is I would use 98 Caltex. If it's not I'd use the 98 with either a fuel conditioner in the fuel line somewhere or just using an additive you can get from super cheap and the like. I've always been advised to stay away from shell, apparently can foul up your valves.

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82 UK import... so leaded... the reason I ask is I know from my old VW`s some run great on 91 unleaded yet run like a hairy goat on 95 or 98... and vice versa

It's strange, my missus's friends Peugeot was designed to run on premium only yet the car rejected everything except E10, even told by a mechanic to run it only on E10. Odd

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I've always gone with the 98 RON BP Ultimate. Shell stuffed up there higher octane fuel many years ago and got a bad reputation because of it, many still remember that and avoid it.

I now run 7 Eleven's 98 premium, it's Mobil supplied fuel and cheaper than BP 98 Ultimate.
My C/R is 11.0:1 and it doesn't ping.

I gave up on Caltex 98 when I got a bad load of fuel.. and barely made it home. It swelled the jet's fuel line shut on the HS6.
I binned the aftermarket (made in Oz) jet and bought an SU one. God knows what that fuel was...

I don't have unleaded inserts (valves too big), Flashlube keeps the seats and valves shiny.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

http://www.mynrmacommunity.com/motoring ... d-you-use/

NRMA gives a simple over view, but our car's don't have a knock sensing dynamic timing advance as part of an integrated ECU. Instead we get crusty old distributors, so no power of efficiency increase.

If it runs fine on 91, then it will run fine on 98, but not improve anything other than the length of time the fuel takes to deteriorates to a point where pinging occurs. No problem if you drive it and fill it up at least once a month. Octane doesn't improve power unless your engine needs to have it.

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can you read the engine number? it could be a factory high compression engine with 10:1. this would need 98 RON

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Rover 214 atm ....

One cheap way to boost octane is to ad toluene.... (which is about 50% of Aus petrol anyway). However, one downside of excess is softening and swelling of rubber fuel lines.... conversely, too little can cause the opposite (hardening and shrinkage).

Some years ago there was a spate of under bonnet engine fires in NZ that was traced to a tanker load toluene over endowed fuel from Singapore...

As Mick said, octane is something you need just the right amount of - any more is just wasted money.. Try a tank of cheap stuff - if it pings add some octane booster and try something better next time.

Cheers, Ian

I have an 1100S with a H in the engine number. Does that mean that it is 10:1 and therefore need to run on 98.

I currently run my MY05 STI on 98 from the local 7eleven and it goes like the proverbial off a shovel.

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No. That means it had the standard compression ratio for that motor.

Which was 8.8:1. Only the Cooper S and GT back then got the 9.75:1 pistons.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I have tried 91 and 98 octane in my 998, and (as expected) there was no real change. Power felt just the same, and fuel economy was no different.

If you increase you cr and/or advance your timing for 98 octane, I have heard from too many people that the shell brand is hit and miss. Most people swear by BP.