Which is worse... leaving a car running or starting and stopping the engine?

Employees of the company I work for drive their own vehicles. On a “Driving Route” day they may visit 200+ homes in an area, one after the other, for from 1 to 5 minutes.



The options: Leave the car running (and risk it slipping into gear and running into something or someone or it getting stolen) OR turning it off and taking the keys (and risking damage/increased wear to the starter/engine) Help!

I’ve leave them running only if you have another key such that you can lock them. I don’t see any realistic risk of them slipping into gear, if they are automatics. Either way, use the parking brake.

Leave running - extra fuel use, more pollution, some increased risk of theft.

Turn off - more starter wear, very slightly more engine wear.

Generally speaking, I’d vote for turn them off.

I would second tardis’s answer in most cases.

Is there the possibility that they could park the cars in the vicinity and visit the homes by bicycle? There exist very good folding bicycles (Giant and Dahon) that fit neatly in an average car trunk.

Q2Jester here… We use bicycles on some routes - but most of the ones mentioned about are too long, or the homes are too far apart… In the past 15 years we’ve had about 10 cars stolen. In the same amount of time we’ve had about a dozen run away vehicle accidents…

When you leave the engine running, you (obviously) increase the odds of auto theft unless you have an extra key to lock and unlock the door while the engine is running.

If a vehicle is stolen and later recovered with no evidence of jimmying the door lock and the ignition lock, the insurance company may disallow claims for damages to the car. Even if a car is not stolen, the chance of a child slipping behind the wheel to “play” with the car makes the company liable for incredible damages if the child is injured or killed and/or someone else is injured or killed, and/or if someone’s property is damaged by this “attractive nuisance”.

Thus, I would not recommend leaving the engine running.

Yes, replacing starters can be pricey, but when you compare those costs to liability and insurance issues, the cost of a starter seems paltry by comparison.

I would take that as really good indication that you need to shut them down while stopped.

Roger That! Thanks Tardis… Needless to say: “I’m building my case”.

If I were using my own car I’d turn it off every time.

Get an hybrid. They are designed to turn on and off all the time. Their starters etc are designed for the task.

You should not leave an unattended car running, end of debate.

Whatever they like doing best. It is a close which is actually better.

Our city has a firm “no idling” bylaw, and city employees are told to shut off their vehicles if they are stopped for a certain pre-determined lenght of time. Only police cars and busses are exempted, for obvious reasons.

The city’s reasons are less pollution and less fuel used, as well as longer times between maintenance.

Because they’re driving on company business, the company should have a rule that they MUST shut off the vehicles. Too much potential liability for the company otherwise. What someone leave a car idling, goes to drop off the stuff, and somebody steals the car and kills a pedestrian. Who’s going to get sued? You guessed it!

Depending on what kind of business it is, hybrids can be VERY expensive. If it’s some kind of delivery route like Fed Ex or something similar, then you’re talking about those $50k Suburbans. If it’s a postal courier type, then they could get away with something like an Escape. Pizza delivery would be a Prius’ dream come true

For several years I contracted a route driving trucks that I owned over 300 miles each day making many stops. I also serviced trucks for other drivers. Everyone tried every possible trick to cut costs and it was an overwhelmingly obvious increase in expense to leave the engine idling even for a few minutes at stops.