Gas for a 4.3

[bobdec]

First - Don't assume the automotive gas station higher obtain is ethanol free, high obtain fuel may contain more ethanol (full 10%) as it is an cheaper octane booster. All stations are different, some only sell 100% gasoline for recreational use only. Do some searching or look at http://pure-gas.org/

Secondly - Newer engines have no problems running with the 10% ethanol. HOWEVER prolonged storage of E10 which is very common in marine applications is a problem. The problem manifests with extended storage in the tank (water separation) an it can wreck havoc. Water fuel separators/filters and "marine ethanol stabilizers' will help in that case. By the way my marina only pumps 100% 89 octane, buy all my fuel there..

 

[roffey]

First - Don't assume the automotive gas station higher obtain is ethanol free, high obtain fuel may contain more ethanol (full 10%) as it is an cheaper octane booster. All stations are different, some only sell 100% gasoline for recreational use only. Do some searching or look at http://pure-gas.org/
Secondly - Newer engines have no problems running with the 10% ethanol. HOWEVER prolonged storage of E10 which is very common in marine applications is a problem. The problem manifests with extended storage in the tank (water separation) an it can wreck havoc. Water fuel separators/filters and "marine ethanol stabilizers' will help in that case. By the way my marina only pumps 100% 89 octane, buy all my fuel there..

thanks for the web site.

• All Canada: Shell V-Power
• New Brunswick, Newfoundland, Nova Scotia, PEI: all premium grade gasoline
• British Columbia: Chevron 94
• Ontario: Costco 91; Canadian Tire 91; Esso 91; Ultramar 91

 

[QC]

I am going to move this to non-repair I/O. We like to keep the Boat section free of engine stuff....

1) 87 is fine. All that matters is what Merc says
2) Merc Synthetic is the factory recommendation. All that matters is what Merc says
3) 10% Ethanol is OK with Merc

Sorry to be OEM centric, but they are really the ones that we should rely on.

Have fun. Be safe. Looks like a nice ride.

 

[Fleetwin]

Some thoughts on this:
1) Higher octane (premium fuel) does not translate to more power. It's advantage is that it is less prone to detonation. properly tuned your engine will not have this issue.
2) Higher octane is advantageous only if the engine is fitted with a knock sensor that feeds the engine management system which in turn can automatically advance and retard timing as needed. Without this feature you are wasting money.
3) Premium fuel is required only in engines that have high compression and no means of automatically advancing and retarding timing based on engine load (again -- knock sensor needed).
4) If the manufacturer specifies premium, use premium. If they specify 87 - 89 octane, using anything other than that is a waste of money.

Perfectly stated. You DON'T need premium.

DO stay away from E15 and E85.

Also stated, fuel stabilizers are a good idea if the boat sits for extended periods. Can't hurt.