‘ However, some of our race fuels are more bespoke. When it comes to fuelling high-performance, highly-stressed engines, it is always advisable to test thoroughly, including on a dyno, before making any fuel changes. The same approach really should be taken whether switching a race engine to a sustainable fuel, or from one fossil fuel to another.’
If you were to build an engine, knowing it would only be run on Sustain, is there anything you could do to adapt it to work perfectly on the fuel?‘ Modifying engines to allow them to run on sustainable fuels is not always necessary, contrary to some beliefs still out there.
‘ For road cars running on Sustain Classic, no changes would be needed at all. For race-prepared engines, you will likely want some form of modification, even if it’ s just an ECU tweak, carburettor tune or, if changing to a grade the engine wasn’ t designed for, physical hardware changes. It’ s worth pointing out that fuel-injected engines running ECUs( and therein, lambda) should be able to deal with most variations presented by the slight difference in properties of the sustainable components within our fuels. Once upon a time, biofuel was mostly high-ethanol fuels, which, by contrast,
Coryton takes agricultural by-products or waste from crops or food manufacturing that wouldn’ t be used for consumption to create its fuels do require engine modifications to run properly. Whilst those fuels still have an important role to play, there are now many sustainable fuels which contain little or no ethanol.
‘ By having a wide range of fuels available, if an engine did have particular requirements, then we would choose a fuel that best suited the engine, rather than the other way round. Minor tuning adjustments, like changing jets, for example, can be used with carbureted engines to achieve smoother operation. However, these instances represent a very small percentage of use cases, almost exclusively in historic racing, and we wouldn’ t envisage anything beyond this needing to be done for an engine to run optimally on sustainable fuel.’
There has to be a hitch. There is, and that’ s the price. Sustain 80, Coryton’ s fuel you might use in a modern petrol performance car, costs around 3.8 times the price of even high-octane pump petrol. While that might be a cost the odd enthusiast could stomach for taking out their weekend toy for a quick blast, it’ s simply not going to work for most people. What’ s the solution to reducing the price and therefore introducing the advantages of biofuels to the masses?‘ The industry needs more government support. We need to have a technology-neutral approach where different solutions are used together to greater effect. Different solutions can meet different requirements. It’ s rarely the best idea to focus on a single solution approach.’
Summer 2025 The Engine Rebuilder 43