Subjective, for sure - but I really do believe I get better overall performance (idle, acceleration, etc.) with Chevron premium fuel (93 octane) in my gassers. Over the years, I've tried both Chevron regular (87 octane) and mid-range (89 octane) and just don't seem to get the same performance. I suffered no ill effects, except a 'feeling' of less-than-peak performance.

There is one exception - my '96 SL600 would not pass smog in California due to the ECU's 'Not Ready'... until I moved to Texas and used one tankful of Chevron premium (93 octane). In California, the highest, readily available was 92 octane. After only one tankful, the computers all came up 'Ready'. Can't explain it; neither can Mercedes.

Regardless of all that, good luck.

Cheers,
Jeff

__________________
MBCA Member #B012089 (Lone Star Section)
OBK Member #47 (W123 Division)
'96 SL600 (105K) Triple Black - Mein über-Fräulein
'79 240D (292K) Yellow/Saddle - Mein Spielzeug
'01 ML430 (123K) Black/Saddle - Wife's Ride
'94 SL500 (164K) Green/Champagne - Daughter's Dream
'73 450SL - RIP
'86 300E - RIP
'88 420SEL - SOLD
'94 S320 - SOLD