leRoy Troy's version is as follows:

The old spare tire ain't what it used to be,
Ain't what it used to be, ain't what it used to be.
Can't even tell where the retread used to be,
Many long years ago.

The old grey mare is back where she used to be,
Back where she used to be, back where she used to be.
The old grey mare is back where she used to be,
Many long years ago.

She might be old and lean, but she don't need no gasoline.
Yes, the old grey mare is back where she used to be
Many long years ago.

The old grey mare is gettin' more attention, gettin' more attention,
Gettin' more attention, than a widow with a pension.
Yes, the old grey mare is getting more attention,
Than she did long years ago.

And, with all that attention, she's gettin' quite a temperament,
Gettin' quite a temperament, gettin' quite a temperament,
Why they bobbed her tail and gave her tail permanent,
Like they did long years ago.

The farmer hurries home, and grabs the curry comb.
The kids all rush out to the barn, give her oats and hay,
Didn't mean no harm.
Yes, the old grey mare is gettin' more attention
Than she did long years ago.

The farmer and the old grey mare,
They stand by the side of the thoroughfare,
And they make more money standing there, than they did long years ago

The cars a go a speeding right pass, going mighty fast
As they go a whizzin' right past.
A few more miles down, they a'run out a gas,
And the farmer pulls them home.

The farmer gets ten bucks, for towin' cars and trucks.
He's the one they all called a boob, called him a hick,
Called him a rube.
But he ain't got no flat inner tube.
He and the old grey mare.

The garage of yesterday, is full of oats and hay,
And, stead of talking about oil and gas,
They're talking oats and hay, corn and grass.
Yep. The old grey mare is back where she used to be,
Many long years ago.