How long can I let a car sit without being driven?

February 26, 2020 9:15 AM

Mr. BlahLaLa is recovering from an injury and can't drive his car. How often do I need to drive it to keep it in good shape?

It has been one week since Mr. BlahLaLa has driven. It will be at least two weeks more, but up to five weeks more. The car is safely garaged and won't be subjected to very hot or cold temps. It's a Honda Insight, so a hybrid. It has a brand-new battery.

Given those details, do I need to drive it at all? (I don't love driving it but I will if I have to.) How often do I need to drive it ? When I drive it, how long a drive does it need to be?

Thanks.

posted by BlahLaLa to Grab Bag (15 answers total)

If it were me, I would take it out on errands at least once a week.
posted by Medieval Maven at 9:24 AM on February 26, 2020 [2 favorites]

This advice comes from my mechanic dad, when I asked him the same question about a year ago. Drive it once a week, long enough to get the engine nice and warmed up. About 20 minutes or so. If you're comfortable just taking it out on a highway with no stoplights and opening it up (if you have such a thing near you), then that will do the trick. I always preferred driving on the open road than in the city with stops, turns and pedestrians, myself.
posted by backwards compatible at 9:25 AM on February 26, 2020 [6 favorites]

About once every 6 or so weeks. And you don't need to drive it, just back it out of the garage into the drive way and let it idle for 5 minutes.
posted by The_Vegetables at 9:26 AM on February 26, 2020 [2 favorites]

My source is me. I have a car that I drive less than 1,000 miles a year, and leave it for 2 months or more often on when I work from a different city. The battery is starting to go bad after 3 years of this, but other than that, no major issues.
posted by The_Vegetables at 9:27 AM on February 26, 2020

This is the opposite of good advice. Due to some complicated family reasons, I let a truck sit in my backyard for 6 months in temperate, dry weather with no driving. At the end of 6 months, it would not start and cost about $1,200 in repairs to get it back working. (it was a diesel which are prone to growing algae in the fuel tank if not driven but even gasoline engines can attract water moisture in the fuel tank if let to sit for too many months)
posted by caveatz at 9:38 AM on February 26, 2020

My understanding is that hybrid batteries are more prone to problems (and far more expensive to fix) if they sit. I would call the dealer.
posted by veery at 9:43 AM on February 26, 2020 [2 favorites]

Best answer: I would like to politely split the difference between two pieces of advice. My experience is someone who often has a third "fun" car that I don't daily drive. I would suggest that you could do it less frequently (once a month or so), but that when you do it, it should be for twenty minutes or more, if possible. Even in a very modern car, if you just run it for five minutes, you will possibly build up carbon deposits on the intake runners, which in the case of my current fun car makes it idle poorly sometimes. The car doesn't reach operating temperature (and burn off some of the deposits from the initial richer mixture of gas-to-air) usually for about fifteen minutes.

If you are talking about letting the car sit for one time up to five weeks, though, I would just suggest that you either just let it sit that whole time (it will more than likely be quite fine), or take it on one longish highway trip (30-45 minutes) in the middle. With my current fun car, I try to take it to one of the farther-away city library branches once a month, so it gets a good 30 minutes twice in a row, with some city and some highway.
posted by Slothrop at 9:46 AM on February 26, 2020 [2 favorites]

Hi! I had a Honda Civic Hybrid that I inherited from my father, who let it sit for a few months. The battery pack failed and needed to be replaced, and I got a scolding from the Honda dealership about how you shouldn't let hybrids sit.

Take it out for errands at least once a week.
posted by rabbitrabbit at 9:54 AM on February 26, 2020 [4 favorites]

Agreed that its being a hybrid is very relevant here. We've let our hybrid sit undriven for a week or even two with no problem, but longer than that I'd be sure to drive it.
posted by LobsterMitten at 9:55 AM on February 26, 2020 [3 favorites]

As it is garaged, you don't have to worry about driving it to keep the authorities from deeming it abandoned. Mechanically, you will probably be fine if you don't drive it at all during the period you mention because 1) it is a Honda and 2) no other reason is needed, but also it is garaged. It certainly won't hurt to take it out once every week or two, but if you do, drive it enough that the gas engine starts up and runs for a while.
posted by kindall at 10:41 AM on February 26, 2020

As it is garaged, you don't have to worry about driving it to keep the authorities from deeming it abandoned.

As long as it has current tags and is on private property, you can leave it as long as you want. Local regulations differ for street parking, but are generally longer than 2 weeks in front of your own property, minus things like street sweeping rules, etc.
posted by The_Vegetables at 11:03 AM on February 26, 2020

I was told three weeks absolute max on my older-model Priuses, and as my starter battery (in the Prius that's a deep-cycle marine/AGM battery) got middle-aged it could not tolerate two weeks - I had to jump it after two and even though I drove it around for several hours of errands that day it crapped out permanently after the next time it sat two weeks. Normally our batteries last 5+ years but this one only lasted 3.

You really do need to drive it around for at least an hour, which sounds like you're not going to love. Maybe call your dealer service department and get their official word on how long to safely let it sit? There is probably a documented procedure for disconnecting the battery entirely if the car is going to sit (this is probably in your manual but it couldn't hurt to ask, if they'll answer without you coming in).
posted by Lyn Never at 11:49 AM on February 26, 2020

My now-retired parents are global nomads (not really by choice) and left their Honda Insight with my brother until they can sort out immigration status. He drives it about once every other week, on a 30-60 min round trip.

That said, in the past they would also leave the car at home -- outdoors, not garaged -- on 2-3 week vacations, and it was fine. But I would not let it go more than 3 weeks for sure.
posted by basalganglia at 1:13 PM on February 26, 2020

I have a car that I leave sitting for a couple months at a time. It's fine.

The only thing to keep in mind is that cars today seem to have a lot of computers that keep running even when the ignition is off. They don't drain much, just milliamps, but they can add up over a couple of months. So your battery won't be dead but it may be at a lower charge than optimal.

So it might be a good idea to clip a cheap $20 trickle charger on the battery if it is going to sit for many weeks on a regular basis.

But in your case, if this is a one time thing I wouldn't do anything at all. It should be fine.
posted by JackFlash at 9:11 PM on February 26, 2020

Response by poster: I never did get around to driving it (didn't feel the pressure to, after your answers, though I would have if this had dragged out any longer). It ended up being 21 days total that Mr. Blah couldn't drive, but once he did the car was totally fine. Thank you!
posted by BlahLaLa at 1:44 PM on March 10, 2020 [1 favorite]