Confession time guys! I don't believe in changing my oil once every 3,000 miles like they recommend. I change mine about once every 5,000 miles or so. Will this hurt any of my cars?

My opinion is that 5k miles is perfectly fine. Some of us discussed this before in this thread: Ways to save on Oil Changes.

4k-5k is supposed to be optimal, so I hear..

Yeah as far as I know it's fine. One of my cars tells you when to change it based on viscosity, not on mileage, and it usually works out to be around 4500 miles.

It all depends on your oil. Synthetic oils can run between 6k and 10k miles. Mercedes uses an oil that supposedly will last 10k miles in their new cars.

Regular dyno oil can run between 3k and 5k depending on the age of the car. Older cars should have it changed more often.

depending on the oil and your car i wouldn't go much over 5000 miles. they have recently proven that the quality in oil nowadays had gone up quite alot so you really don't have to change it every 3000 miles anymore. on that note i don't care how many miles i put on my oil i usually try to get it changed asap when its get brown.

I change mine every 3000-3500

Depends on the oil. If you're using the 7-11 brand I wouldn't use it for more than 3500 (I wouldn't use it at all, I'm just saying). I know guys using full synthetic that are getting a pretty good stretch. One of which has an '81 Chevy p/u w/ a rblt 350 and his oil still looks pretty fresh till at least 5000 mi. He said he changes it about every 7500-8000 miles and as far as I know, He's been doin it that way for the last 4-5 yrs. As for older engines need to be changed more regularly, unless you're using an engine from the mid-50's or earlier. I wouldn't say that's necessarily true.

History lesson time....
Up until that point in technology (mid-50's) much of the oil was produced from Pennsylvania, hence companies like Pennzoil and Quaker State. The oil from PA was much higher in petroleum content than oil we now use from Texas (Texaco). This was optimum for running in engines of that era because the engines were milled with larger lubrication passages. The oil from PA is actually still a better lubricant due to higher viscosity from the high petroleum content. However, when the Ford Motor Company started to design engines with tighter tolerances and thinner oiling passages in the mid-50's, PA oil could not be used because it was now too thick for the oil passages and would start to build up petroleum reserves in the valvetrain area. The oil from Texas is thinner and generally better suited for these engines as well as subsequent designs. That is why Texas is the leading oil producing region in the US. PA still produces plenty of oil, however it is lower in Gasoline content and again, a thicker, petroleum based oil. This is not to say that if you use Quaker State or Pennzoil with a newer engine that it will clog up. These companies all get from the same refineries (overseas I might add) and it all comes back the the same viscosity grades. So, unless you're trying to build extremely high hp engines from what would be considered "antique" blocks and heads, you shouldn't have much of a need for changing your oil more frequently, at least not noticeably.

My car burns a quart and a half every oil change... I need a rebuild lol