Lukaboy

We're returning a rental car to London area early October. We're coming from the north. We'll be seeking shuttle/tube to hotel in Earl's Court. Should I return car to Heathrow Terminal 3, Terminal 5, or other?

AlienInTheFatherland

This will depend on which company you are hiring from.

As far as I know only Avis has in-terminal facilities (at T5 short-term parking). All the other providers are, I believe, off-terminal, so you return the car to the off-terminal station and then get a bus to T2/3 to get the tube from there.

12939

As AlienInTheFatherland says, generally speaking, the rental returns are slightly off-airport and mostly not very convenient for any onward transport except for taking their shuttle to one of the terminals and onward travel from there.

However, the OP might be interested to know that the main Heathrow branch of Sixt is right by Hatton Cross Underground station (Piccadilly Line direct to Earls Court) on the A30 Great South-West Road. The entrance for car returns is via the BP petrol station forecourt. No bus required, just cross the road at the traffic lights and you're at the Underground station.

There is also a small Sixt branch at the Sofitel at T5 but that really caters to returns that were rented from there unless you specify it as the return location. They're not geared up for random drop offs or pick ups. This would be less convenient for the OP anyway as it's a much longer walk to the Underground.

stut

Avis also has a drop-off point at the Westfield Shepherds Bush shopping centre, which could be pretty convenient. There's a direct train to West Brompton, otherwise it's easily cabbable.