How do I … Choose the right grade of fuel? – WHEELS.ca
Choosing the right grade of fuel for your car or light truck is as easy as consulting the owner’s manual or even reading the label on the fuel filler flap. Where is it?
The reality is that in some cases you may be able to use a cheaper grade of fuel in a vehicle that requires a premium.
If your manual or the fuel door label says “premium grade fuel recommended” then yes, you can absolutely use regular fuel. However, you may see a slight reduction in performance or even economy. As an example, the 2.5-liter turbo versions of Mazda’s CX-5 crossover are rated at 250 horsepower on 93-octane super fuel. regular 87 octane, which Mazda considers quite acceptable for full-time use in this model.
Where the vehicle manufacturer’s literature or gasoline door decal states “premium fuel required”, additional caution is required. The “octane number” of a gasoline mixture is actually a laboratory-derived measurement of its resistance to uncontrolled spontaneous combustion of the fuel / air mixture inside the cylinder, called “knock”.
Modern engine controls can detect and attempt to dampen knock – which in severe cases can actually break components like pistons, connecting rods, and even valves – but they are not foolproof. Using a fuel that is less sensitive to shock is the first line of defense against this.
If you have a supercharged or supercharged engine – often found in high-end or performance models – the conditions inside the combustion chambers are more difficult than those in traditional vehicles with less stress. In these cases, you should probably stick with the car manufacturer’s recommendation.
If your car has a listed premium requirement, but you’re not overly concerned with maximizing performance, the safest strategy would be to add regular fuel one tank at a time and observe any change in operation. or the presence of a metallic clicking noise when accelerating. If no problem arises, add another ¼ tank and keep one eye (and one ear) out again. Hopefully, you should continue with the lower grade fuel, keeping in mind that prolonged hard acceleration should be avoided if possible.
Keep in mind that if the vehicle is still under warranty on the powertrain, you could void it if something went wrong and it could be proven that you did not meet the manufacturer’s requirements. In this case, the cost-benefit ratio is probably not worth it.