Long term storage of oil, other fluids in trunk?

My mechanic suggested that I should rotate my supply of emergency fluids (oil, tranny fluid, power steering, brake, antifreeze) every six months, because they are exposed to temperature fluctuations and because they degrade.



His argument was that the car manufacturer tells you to change the oil every 7500 miles or six months, so even the stored oil would needed to be swapped out every six months.



Well, I disagree and am seeking second opinions. Thanks for your input.

I also disagree.

Stored in the original sealed containers those products will have a very long life.

Once installed or opened, they will be far more subject to aging.

These products, if stored in their original unopened containers, will remain fresh for a lifetime.

I don’t know why you carry them aound in your trunk rather than store them in a closet somewhere, but your method should not normally pose a problem.

Most plastic containers degrade and start leaking after about 3 years. A hot trunk will accelerate this. A big mess to clean up.

I used to have a Tempo. I never had a chance to worry about my stored fluids. Six months would be way too early anyway.

Most plastic containers degrade and start leaking after about 3 years.

Could be, but it need not be. While I have had oil products far longer than that and I have never noticed a problem, I have not stored them in my car, They are in my garage.

In any case I would hope that no one would have reason to store them that long in a trunk, they should be used before that.

Given these fluids are used in an emergency besides the motor oil and will likely leak back out quickly I don’t think it matters. T

he motor oil even if 5 years old in a sealed container hopefully is just for topping and will be diluted by what is in the crankcase. Also it will be drained out also too.

I wouldn’t worry about anything other than the brake fluid.

For the brake fluid, if the seal isn’t perfect, I wonder if you could get enough condensation at the top of the bottle with the temperature swings over time to contaminate the fluid a bit. Water in brake fluid is bad news, of course. Also consider that brake fluid would be nasty stuff on your carpet and paint if it happens to leak.

His argument is bogus. Oil in the engine is subjected to heat, shear forces, particulate contamination, dilution from blowby, and contamination by blowby. Oil in the bottle isn’t. The lifespan of oil in the engine has absolutely nothing to do with the lifespan of oil in the bottle.

  • mountainbike