change oil

i have a 01 stang and it has 40k miles and i havent changed the oil. i probaly will in a few days so is that bad for it at all?

Who knows when it was last changed? Could've been just 1 or 2 thousand miles ago. Could've been 7, 8, 9 thousand miles ago. I'd change it now, and start keepin' tabs on it from now on. Lots a guys change it at every 3,500 miles. I change mine at 5,000 miles. (V-8)

Not knowin' what was it in before, you might want to ask your mechanic whats a good 'neutral' oil that your car will adapt to.

I agree with b3warnick about the changing oil and tabs on the intervals
I would do one more thing though,,,if you know or have an idea how long its been since last change and it has been over 8000 since its been changed then you may want to do a back to back change,,,this means do a change using 10/40 and run her for 100 miles to loosen up and heat up the engine and all its components. The change it again when she is hot and let it drain for a while ie: 3 hrs to let all dirty oil drain completely, then put for summer use a good 10/40 oil like Valvoline and in winter use probably same thing,,the factory prob calls for 10/30 or 5/30 but after 40k you tend to get clearences in the engine pending on how it was driven and 10/30 just doesnt take up the clearences . Good luck!!

I change mine @ 20,000 miles, but I use Amsoil.

If you are saying that you have waited 40,000 to change your oil, you have some major issues.

I swear by synthetic oil. Mobil has a new one that lasts 15,000 miles - sounds like you could use this if you let those many miles roll up before changing it.

I change my oil ever 2500 miles. There's just something about letting oil stay in my motor for a lone period of time. Even if it is state of the art oil and does not breakdown, it still gets dirty all the same.

I swear by synthetic oil. Mobil has a new one that lasts 15,000 miles - sounds like you could use this if you let those many miles roll up before changing it.
just make sure you install a quality filter that can filter at that 10-20 micron level.all those cheap oil filters dont cut it.they only filter down to 50 microns and a large percent of engine wear is caused by particles much smaller than 50 microns.