Before. Moisture and contaminants can get into the oil. Not to mention carbon, nitrogen, and sulfur oxides from combustion can get into the oil along with the moisture and create slightly acidic conditions which can corrode the engine.

I do both before and after.

I just did an Oil Change last month. That oil will sit in the car from the time I put it in the garage at the end of November till next spring. At 11-12 bucks a qt for RedLine I cant be changing it left and right.

The use something cheaper before storage.. whatever name brand synth that is on sale.

Yea I guess I could do that. How long you guys storing your cars for winter?? Last year my Z went to sleep for about 4 and a half month Dec to about maybe middle of April. This year I think I'm gonna be putting her away in the begining of Nov and not take her out till April at some point.

Im pretty much the same as you... and I plan on doing what you did. Just got it changed a few weeks ago, not doing it again until after the break... I think people can get a little paranoid with certain things. I know people who have stored their cars in the winter without an oil change and never had a problem... Actually, now that I think of it, I dont think ive actually heard of anyone ever having a problem by having their old oil sitting in the car for storage. Also, whats the difference if the car is stored or not, it still has the same oil running/sitting in it regardless of being stored or not...

I think the difference is when you run the engine, then the heat vaporizes some of the moisture and acid away. If the oil is cold and stagnant, that doesn't happen.

Always before storage.

If you leave older oil in then change it (and the filter) before you run the engine after it's been sitting. I just can't believe how some people try to save 50 cents to pay a dollar later.

Oil is cheap and if you have to leave the car sitting for a while in winter, factor that into the purchase price of the car. Is $50 for an oil change really more than you can afford?

I understand your point but i just got it done. I honestly dont think it would do any damage myself but doing so gives people some peace of mind... It really will depend on how many miles i have on the oil before storage. if i only put on 500 miles, im not going to do it. If i have 3000, then I probably will...

Honestly, I think it would be fine without changing the oil before storage too.. But I do it anyways. Part of it is peace of mind, part of it is having one more service day with my girl before I don't touch her again for months..

It's nice to just know I've done as much as I can to keep her running strong down the road.. I plan on keeping my Z for as long as I can. If fresh oil pre-storage for the life of the car gives me one extra year before an engine rebuild - I'm glad that I did it.