Ethanol might not be good for your engine

For those looking for safeguards against the ravages of ethanol-blended gasoline, there are a number of precautions you can take.

The first is to simply avoid it in the first place. Dan McTeague, a noted petroleum analyst, says Shell and Esso 91 are both ethanol free. All other grades from the companies have some ethanol content, but the mid-grade blend is pure gas, which means it not only corrodes less than ethanol blends, but is less likely to deteriorate when stored.

Don’t be misled into thinking higher-octane gas contains less ethanol. In fact, it has more. The octane rating of pure ethanol is 100, but when it’s blended with gasoline, it performs as if it’s 112. In other words, higher-octane blends — Petro Canada’s 94 and Esso’s 93 — use more ethanol, not less.

For those storing their vehicles for the winter, specialty gasoline makers — yes, there are boutique gasoline manufacturers — offer ethanol-free formulations specifically tailored for a long shelf life (as much as two years). For those on a budget, a trip down to Canadian Tire for some fuel stabilizer is usually good enough to preserve your pump gas — use that Shell and Esso 91 stuff — over the winter.

A little creativity — and common sense — can help here. For instance, when I ride my classic 1982 Honda CB1100R frequently, I’ll often fill up with Petro Canada 94, which does contain ethanol, for its higher octane, but the gas is never in the carburetor long enough to cause damage. However, whenever I know she’s going to be laid up for a while — especially over the winter — I make sure the last tank I run through her is ethanol-free.

That applies to other vehicles too. For instance, the point of the modern PHEV is to actuate the gasoline portion of its drivetrain as infrequently as possible. For particularly careful owners of longer range PHEVs — Chevrolet’s Volt comes to mind — that can mean refuelling as infrequently as every three months. So a careful Volt owner will want to ensure that ethanol isn’t gumming up the car’s drivetrain.

More troublesome for older, carbureted vehicles is that ethanol is 35 per cent oxygen. Burning it can cause an older carbureted engine to run “lean” — combining too much air with too little fuel. In mild cases, it can cause older engines to stumble, spit and cough. In a worst-case scenario, it can even lead to catastrophic — as in big, gaping holes — piston failure.

For the true gear head, yes, that does mean that the very thing you’re trying to prevent — the “pinging” caused by lower-octane fuel — is exacerbated when you fill up with premium 94 because your hot rod is now running hotter thanks to a leaner mixture.

It’s a paradox, but forewarned is forearmed.