which grade of fuel to use?

[gride300]

just put some stabil in when you fill up with 87.

[engkid_486]

just put some stabil in when you fill up with 87.

Is that necessary if you intend to go out consecutive days (refilling with fresh gas each day)? Is it incorrect to start off using 87 in the beginning (of weekend) and on the last day fill up using 89 (therefore some 89 is left in the tank for the 3 - 5 off days)?

[gride300]

do not change the grade of fuel. stick with 87. you can use stabil as an every fill up additive if you want. it'll help keep some of the condensation out of the ethanol. you use far less than when using for storage.

[ronskal]

Well as the proud owner of a new 210 (thanks all for your opinions etc. on that deal). I have read most of the literature. The PCM owners manual stated words to the effect that they recommend 87 but the engine may sense detonation/pre-ignition at that octane and 89 would prevent that.

OK, well then I run 89 just like my MC with the Indmar 5.7 said to do.