Originally Posted by Jeff Lange

It's not "so they say", it's because it has a direct-port injection system. The pump in the tank is a low-pressure supply pump for the high-pressure mechanical pump on the engine. All D4/D4S engines use the same system. Building the car with a high-pressure electrical pump in-tank (less reliable) and then having high-pressure lines running the entire length of the car instead of simply using a mechanical pump on the engine with a very short line makes little sense. Sports car or not, you need high-pressure for direct injection (approximately 2000psi), and the best way to do that is with a dual pump setup like all Toyota/Lexus/Scion D4/D4S cars have. Most DI systems from every manufacturer are similar.



The IS250 has 2 pumps, the IS350 actually has 3 fuel pumps, the direct injection low pressure supply pump (in tank), the direct injector high pressure pump (on the engine), and the port injection pump (in tank).

Jeff

Originally Posted by Jeff Lange

Tank does not need to be dropped to get the fuel pump on an IS250. It is accessible from under the rear seat.

Jeff