My wife and I have a 3rd vehicle (pickup) that we really don't need to use very often so it ends up just sitting in the driveway quite a bit.

I believe that a vehicle should not be left to sit for extended periods of time without starting it up occasionally and getting the fluids flowing. So at least once a week I drive the vehicle for a few miles if I need to take a short trip somewhere. I've always thought that rust and corrosion would be more likely to develop under the hood on a vehicle that just sits for extended periods of time as opposed to one that gets driven at least once a week.

A friend of mine disagrees. He says that I am causing more damage to the engine by starting it up once a week because the oil has so completely drained out of there after that long. He says that I should just let the vehicle sit for as long as possible until I really need to use the vehicle because that would limit the number of times that I am starting it up with all the oil so completely drained out of there, thereby extending engine life.

So who is right? What would be best for the vehicle?

Dave

Engine oil drains out of the top end of an engine much faster than your friend thinks.

Have him explain to you why the oil stays there if you were to drive it once every few days, but that magical week somehow drains all the oil into the pan.

It only takes a matter of hours really. Leave a vehicle sitting overnight, and there will vitually no oil at the top of any engine. It's something called gravity that makes it happen, I think.

Perhaps the laws of physics cease to exist in your friend's garage?

Edited because I am half asleep and made little sense that first go-around.

Tell your friend to mind his own business.

You drive the vehicle until it reaches the normal operating temperature, don't you?

Vehicles wear out. They wear out if you drive them, they wear out if they sit to much. Both have disadvantages, thats life. As long as you let it get to operating tempurature and stay there for a bit, you should be doing ok. Keep in mind though that the oil takes about three times as long to heat up as the coolant does, and transmissions and differentials need substantial driving(15-20 miles) to really get warm. Also modern Gasoline has a shelf life of only
6 monthes or so, so either use it or only try to fill it with as little as you need, lest you spend $2 a gallon and have it go funky on you.
MV

Seems like this friends advice is along the lines of this: Since the truck just sits for long periods, the oil drains to the bottom of the pan. So every single time it is started it's a "dry start." I think the friends point is that since it is going to be a "dry start" every single time, starting it less often would be better on the engine. Therefore the advice to only start it when "you really need to use the truck" and not weekly "for a short trip or errand," when one of the other vehicles would do.

I understand his thinking, but it's not logical. Whichever car was used for the "short trip or errand" would be getting a "dry start" since the oil drains to the bottom of the pan overnight. Maybe better advice would be to figure out which 2 of the 3 vehicles you really want to keep, then put a little cash into the ol' savings account by selling the other one and eliminate having a third vehicle that just sits in the driveway for extended periods of time.

One other problem with the ocassional short trips is draining the battery. Depending on how short the trip is the battery may not get the charge in needs to replace what it lost while sitting and cranking the engine.