Unleaded Cylinder Head

[Boyscout]

When I overhauled my Mini engine, the head work cost me R2400. This included a resurface, new valve guides, regrind valves assemble etc. R600 of this was for the machining and fitment of hardened exhaust valve seats. so you are looking at about 50 - 60 tanks of fuel to break even. Our Mini does about a tank/month so 5 years to break even.

So yes the fuel additive is the most cost effective way to ensure your Mini does not eat its valve seats. If the head needs to be done anyway, it makes sense to have the seats done at the same time.