octane requirement

[bavardage]

What octane fuel should be used in a Mercruiser 350 MPI engine?

 

[smarks]

Re: octane requirement

89 or higher is going to be your best bet
Regards

 

[Don S]

Re: octane requirement

Here are Mercruisers recommendations.


http://northamerica.mercurymarine.com/serviceandwarranty/mercruiserfaqs/fueloil.php

 

[bavardage]

Re: octane requirement

thanks all for your input and links. The mechanic at the dealership where I bought the bought said I should use 92 octane, jet the link for mercruiser as well as the owners manual say 87.

 

[Don S]

Re: octane requirement

I would stick with what Merc says on their site and the owners manual. After all, they are the one that put it all together, and they want it to work the best for their customers. You Mechanic may just have his own strong opinions, but that doesn't make it right.

 

[jtybt]

Re: octane requirement

Yup, if you read, it said 'Minimum Requirements'.

The mechanic is just 'taking a little heat off his back' by saying 92 octane.

Octane requirement depends completely on how the engine was set up.

I built a 406 CI chev, carbed 325+ HP and 450+ ft/lbs of torque to run on 87 octane.

 

[HT32BSX115]

Re: octane requirement

The mechanic is just 'taking a little heat off his back' by saying 92 octane.

I would bet the mechanic is assuming (mistakenly) like many, that if 87 octane is ok, then 92 must be "better".


That engine was designed to run on 87 octane. 92 octane is simply a waste of money.