I wonder why there is such a variation among people that have the same car with the manual transmission.
It doesn't seem like we would drive that differently as I don't do anything special except my tires are over-inflated,
40 front, 38 rear, and I'm really into looking ahead & coasting & trying to time the lights just right so I never have to stop.
It's like a game.
Last week I was running 1st & 2nd gear up between 3-4,000 rpm, sometimes higher, & then I'd be at speed & would just make my way into 4th or 5th gear.
Even when the car was brand new I got 34 & I drove it really, really, really, really bad. I couldn't get used to the clutch. I'm surprised it still runs.
But anyway maybe try to concentrate on coasting more. Maybe that's the secret.