This car is not up to being repaired

[ROFTOK]

Usually, it's people who are up to doing something. But can it be things?

This car is not up to being repaired. It's cheaper to buy a new one.
This laptop is not up to warrant repair.

 

[Rover_KE]

No.

This car/laptop is not worth repairing.

 

[emsr2d2]

I think you've misunderstood "to be up to". It means that you're capable of doing something.

John: Do you want to climb Ben Nevis this weekend?
Helen: I don't think I'm up to that. My knee still hurts from the last climb.

Sam: I'm going to make a Powerpoint presentation for my talk on Friday.
Sarah: Good luck! Your laptop's not up to that. It's so old it can barely run a simple word processing program!

 

[ROFTOK]

So, if I say:

Are you up to running 5 kilometers? - (ability)
Are you up for running 5 kilometers? - (desire)

I think this makes sense

You have to be up to what you are up for.

 

[emsr2d2]

So, if I say are the following examples correct?

Are you up to running 5 kilometers? - (ability)
Are you up for running 5 kilometers? - (desire)

I think this makes sense.

You have to be up to what you are up for.

Yes, exactly.
"I'm up for it" means "I'm willing to do it".
"I'm up to it" means "I'm able to do it".

 

[Skrej]

Generally, I agree with the feedback you've received in this thread, because you initially had a misunderstanding of the phrase, and how to use it.

That being said, if you were deliberately trying to use personification as a literary device, then you could say something like 'The car just wasn't up to being repaired.'

It's suggesting that the car is an animate object that just isn't able to conjure up the will to withstand yet another repair. Think of the animated (and personified) vehicles in the animated films series 'Cars'.

However, that obviously wasn't your intent in the original sentence based on the additional context.. However, we could use 'up to' with an inanimate object in very limited contexts as a deliberate literary device.

I often refer to my personal possessions as animate objects as an attempt at humor. The other day after dropping and shattering a mug, I commented to my cat who saw the event that "Well, the mug didn't seem to like that stunt very well".

My cat thought it was funny, because she meowed.

 

[ROFTOK]

up to (doing something)

Definition of up to (doing something) in the Idioms Dictionary by The Free Dictionary

idioms.thefreedictionary.com

Here they say this:

up to (doing something)​

Able or willing to do something.

But you said it mean "being able" without "willing"

 

[5jj]

The two examples given in the Farlex Dictionary of Idioms (the source cited the freedictionary) are:

I'm not really up to going to the mall—I think I need a nap instead.
I doubt she's feeling up to having visitors so soon after her surgery.

These suggest ability more than willingness to me.

The Farlex Dictionary also goes on with:

up to doing something​

[feeling] able to do something.
Do you feel up to going back to work today?
She just isn't up to staying up so late.
See also: to, up
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.