Factors To Consider When Choosing A Fuel Pump

When buying a new fuel pump for your car in Australia, there are several factors you need to consider. Some of these factors relate directly to your car’s engine and fuel system and the type of performance you need from your new pump. Others relate to practical concerns such as cost and availability. In this guide, we will cover all the most important points to consider when choosing a new fuel pump for your vehicle.

How to choose a fuel pump

If you want to ensure that you get it right the first time you buy a fuel pump online, you need to do your research.

There is a huge variety of fuel pumps available for both modern and vintage vehicles today, including models designed specifically for performance applications and pumps designed with fuel efficiency in mind. While this wide choice is good for automobile enthusiasts, it can make it harder to choose a new pump for your vehicle. To simplify the task, we recommend focusing on the following two factors when evaluating the different fuel pumps for sale online and in local dealerships:

• Your fuel flow rate requirements 

The most important factor to consider when evaluating fuel pump specifications is the maximum flow rate that each model can maintain. If you buy a pump that cannot deliver the fuel your engine requires, it will not be fit for purpose. Conversely, if you buy a pump capable of delivering a much higher flow rate than your engine requires, you’ll probably spend a lot more money than necessary. 

If you are unsure what your fuel flow rate requirements are, the section below on calculating how powerful your pump needs to be will answer all your questions.

• Your engine and engine bay specifications

There are two main categories of car fuel pumps in use today: mechanical and electrical. Mechanical pumps are designed to work with a carburettor, while electrical pumps work with fuel injection systems. For the sake of brevity, we’re going to assume you’re looking for an electrical pump, as virtually all modern vehicles are made with fuel injection systems rather than carburettors. If this is the case, you need to consider the voltage your engine will be providing the pump, affecting its flow rate. 

You must choose a pump designed to operate efficiently at the voltage supplied by your car’s engine. You also need to consider the available space; is the pump you want to buy going to fit into your vehicle without any modifications?

As long as the pump you choose is designed to operate safely at the voltage it receives and delivers the amount of fuel your engine requires, it should work as intended. If several pumps meet your needs and you find it difficult to choose between them, you may wish to take the practical considerations we mentioned earlier into account as well. 

But before we discuss price and availability, let’s talk about how to calculate your required fuel flow rate.

How powerful does your fuel pump really need to be?

To work out your vehicle's engine's average fuel flow requirements, you need to know its Brake Specific Fuel Consumption (BSFC). If you are happy to use rough figures, you can refer to the industry standards for normally aspirated, supercharged and turbocharged engines. If you would rather work with precise figures, which is the recommended approach, you can determine the BSFC for your engine from the results of a dyno test.

Next, you will need to know the maximum horsepower (HP) of your vehicle's engine. Again, you can take the rough and ready approach using the manufacturer's quoted figures for new engines or measure the output accurately with a dyno test.

To calculate your engine's average fuel flow requirements, simply multiply its BSFC by its HP. The result will be the amount of fuel required per hour in pounds. For example, an engine with a BSFC of 0.5 that develops a maximum of 600 HP will need an average of 300 lbs of fuel per hour. If you prefer to work in litres, one litre of petrol weighs around 1.63 lbs, so, for this example, the final figure will be 184 litres per hour (l/h). A pump that can deliver this flow rate or greater will be suitable for this engine, at least as far as the fuel flow rate is concerned.

Price and availability

Your main priority when sourcing a new car fuel pump should be to ensure that it meets all your needs from a technical perspective. Only once you have made sure this is the case should you move on to practical considerations like cost and availability.

• Cost — If you find two pumps that meet your needs and one is considerably cheaper than the other, you may have found a bargain. However, we recommend sticking to reputable brands and manufacturers to avoid unnecessary difficulties in the future.
• Availability — Spares for readily available pumps are generally cheaper and easier to find, which you might like to bear in mind.

If you’re still unsure how to choose a fuel pump for your car, please contact us now for expert assistance.