Tohatsu and E10 Fuel


Statement from Tohatsu UK

UK - PETROL CONTAINING ALCOHOL (Ethanol) – E10 Fuel


The fuel system components on your TOHATSU outboard are designed to withstand up to 10% (E10) ethyl alcohol (hereinafter referred to as the 'ethanol'), content in the petrol. If possible, always opt for fuels with less or no ethanol content such as super unleaded at 5% (E5)

Although Tohatsu outboards are designed to withstand up to 10% ethanol, we recommend you still take extra precautionary measures when using higher ethanol blended petrol. Also, please be aware of certain adverse effects that can occur under certain conditions. These adverse effects are caused by the ethanol in the petrol absorbing moisture from the air, resulting in a separation of the water/ethanol from the petrol in the fuel system. This separation is more prominent when fuels are left in the outboard’s fuel system for long periods such as 3 weeks or more.


These adverse effects include:

a) Corrosion of metal parts

b) Deterioration of rubber or plastic parts

c) Fuel permeation through rubber fuel lines

d) Starting and operating difficulties


As a precaution, it is recommended by the manufacturer to add a filter which has water separating capabilities when using ethanol containing petrol’s (where possible). Also, check the fuel system for leaks and all mechanical parts for corrosion and abnormal wear more frequently.



A question often asked is why does this very same fuel not affect my car?

In cars etc, alcohol blended fuels are normally consumed long before they can absorb enough moisture to cause problems (daily use), but boats often sit idle long enough for phase separation to take place. Therefore, if your Tohatsu outboard is used infrequently, it is recommended to use a fuel stabiliser (available from your local Tohatsu dealer or chandler). Also, before you put your outboard into storage, it is a recommended to have it serviced and prepared by your Tohatsu dealer. We again, also recommend you use a fuel stabiliser while running the motor before storage.

Storage of ethanol blended fuels for long periods should be avoided in both fuel tanks and fuel systems. please refer to your Owner’s Manual for more detailed information on all the above.

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