There has been a lot of talk about the old 3000 mile oil change intervals. Many in the industry think, and I do too, that we change our oil too often and, it is a huge waste of resources. With today’s oils, I believe that 4000 miles is a better number to use in a severe service area such as Texas. Of course, it all goes back to how you use your vehicle. Temperature, humidity, stop and go driving, and dusty conditions all play into the equation. I think that the best way is to go about 3500 miles and see if it looks dirty, if it looks ok, then go to 4k, or perhaps even 5k. Once you establish a good interval for your driving habits, go with it for a while and see how clean your engine is staying inside. If it looks good, It could save you some money and help the planet.