1988 won't start

[pennyman1]

98 RON is a Australian octane measurement - in Canada, the United States, Brazil, and some other countries, the headline number is the average of the RON (reference octane number)and the MON (motor octane number), called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2. It may also sometimes be called the Posted Octane Number (PON). this gives a number lower than the RON alone. The US trucks had lower compression motors, so 87 octane was fine for these trucks when new.

[geezer101]

98 RON is a Australian octane measurement - in Canada, the United States, Brazil, and some other countries, the headline number is the average of the RON (reference octane number)and the MON (motor octane number), called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2. It may also sometimes be called the Posted Octane Number (PON). this gives a number lower than the RON alone. The US trucks had lower compression motors, so 87 octane was fine for these trucks when new.

Really? What did Mitsubishi do to alter the compression ratios? Or is this due to a different recommended engine tune to meet US emissions? I had a feeling the 4G54's had a lower CR than the G63B engines. Isn't there a label in the fuel filler doors with the recommended fuel type on it? *edit - I mis-quoted the fuel rated on my truck. Label says 97+ octane fuel.