Aeroflow EFI electric in-tank fuel pump

How to Choose a Fuel Pump for Your Build (LPH vs Horsepower)

The Partsman

A fuel pump that can't keep up will lean out your engine at the worst possible time. Here is how to size one properly.

Think in LPH, not just "big"

Pumps are rated in litres per hour (LPH), usually at a given pressure and voltage. As pressure (and boost) rises, flow drops - so always allow headroom.

Rough guide (petrol)

Power Pump (approx)
Up to 350 hp 255 LPH
350-500 hp 340-400 LPH
500-700 hp 450 LPH+
700 hp+ Dual pumps or 525 LPH+

On E85, add roughly 30% - it takes more fuel volume for the same power.

In-tank vs external

In-tank pumps run quieter and cooler and are great for street cars. External pumps suit big power and are often paired with a surge tank to keep them fed.

Don't forget the supporting bits

Adequate wiring (and often a relay), the correct fuel line and fittings, and a filter sized to the pump.

Browse fuel pumps & fuel system parts or call The Partsman on 07 846 1923.