Most miles from a vehicle?
I'm allowing for rebuilt transmissions/transaxles but not engines themselves. (Edit: Valve jobs are fine but no bottom or top end rebuilds whatsoever!)....As for me I drove a 1989 Chevrolet Corsica, 2.8 liter V-6, automatic, to 286k miles (460272.384 km).....The engine was still running but I blew the head gasket as I couldn't trace a leak. It wasn't a radiator or heater hose either. I parked it, bought a wrecked '96 Corsica with a 3.1. If you are familiar with these cars, then just know the engineering nightmare it was to swap out the engines/suspensions/wiring. Yep, I even had to cut out part of the engine bay sidewalls and weld in the new motor mounts from the donor car! (that is, the metal things your motor mounts attach to.)
I haven't driven my '81 Mercedes 280SE in years (ouch...about nine years now!)...It has about 176k miles but a weather-rotted wire to the external fuel pump made it not start up and I haven't yet fixed it.
I'm surprised that nobody mentioned Irv Gordon .....
I consider my "appliance", a 2004 VW Jetta TDI wagon, to be barely broken in at 154,000 miles.
My predecessor to the Jetta was a 1986 Volvo 240 wagon which I drove for 18 years and nearly 300,000 miles. The precise mileage is unknown due to two or three odometer replacements. I make no claims for exceptional longevity for this car either.
Irv Gordon, from New York, is closing in on 3 million miles in his 1966 Volvo 1800S coupe. He holds the distinction in the Guiness Book of the most miles driven in a privately owned passenger car.
Now, to meet the stipulation of the original poster, the engine was rebuilt for the first time at approximately 800,000 miles. Mr. Gordon later decided that had been premature. The second engine rebuild did not occur until approximately 2.6 million miles - or 1.8 million miles later.
Mr. Gordon as put nearly another 400,000 miles on his car since the most recent engine rebuild. This is more miles than I put on my 1986 Volvo in the 18 years before I junked it with a rusted out floor pan and funny noises coming from the rear axle bearings.
I drove my 1972 Volvo 1800E coupe 20,000 miles in the first two years after it was restored. I plan to drive it until I'm too feeble to drive. I hope to put at least 250,000 miles on it before passing it down to my daughter.
Another high mileage Swede
Mr. Peter Gilbert, of Wisconsin, donated his 1989 Saab 900 to the Hartford, Wisconsin Auto Museum in December 2006 with 1,001,385 miles on it.
An AP article reported that at 600,000 miles the car still burned no oil.
The same article reports that the transmission was rebuilt at 200,000 miles and that the hood and other front body parts were replaced after 8 deer kills but is otherwise original.
The AP article also reports that Mr. Gilbert decided the time had come to retire the car when inspection showed the undercarriage was rusted due to the harsh winters in Wisconsin.
It appears this car is probably the record holder for the most miles on the original engine without a rebuild.
For the record, a 1989 Saab is pre-GM ownership.