Hello all, I followed a link from mymonte.com, which is a board I freqently browse and post at to this site. I've been driving my car for the past 13K miles and I've been using Castrol GTX 5W-30 and Purolator Premium Plus and more recently PureONE oil filters. I have not had a problem with this combination, my engine burns remarkably little oil for its age (usually 1/2 quart every 3,000 miles) and is still very strong for what it is. The car had been taken care of its entire life and 5W-30 has been used in it and changed every 3,000 miles or less religiously. Until I started driving and maintaining it, it was subject to almost entirely highway miles and light driving conditions. With the breif history stated, let me tell you a little about my current driving habits. I drive around 35-40 miles per day, but it is not uncommon for me to drive farther...I drive around 300 miles in the average week. I go through about 6 or 7 start/stop cycles per day. I live in a hilly, but not particularly mountainous area, so the car does its fair share of hill climbing, and occasional very sharply inclined roads. I also will confess that I have a heavy foot. My starts are not full throttle launches, but moderate starts usually bringing the motor to 3-3.5K. This is mostly due to the fact that the little 160hp 3.1L is hauling the relatively heavy Monte Carlo and usually a few passengers and a trunkload of stuff. I keep the car out of its 'preformance enhancement' (which engages at more than 70% throttle) mode under normal circumstances. I think I treat the car pretty well. I run regular gas most of the time, but will occasionally treat it to premium. I continue to change my oil every 3,000. My car is quipped with one of those "Change Oil Soon" sensors, but I don't trust it and always change at 3,000 at the latest. Now that you know a little more about me and my car, I think you can better understand my oil situation. As I have said, my car seems to operate well with 5W-30 year round as well as a Purolator PureONE oil filter. I have been told that I should switch to 10W-30 for added protection during the summer months. What are your opinions on this? I am very happy with the PureONE oil filter, but I am running the stock recommened length. The filter my car calls for is the PL10111. There is however, a PL24011 filter which is an extended length which I know to fit my motor. I have been told to use the extended length filter along with a full 5 quarts of oil (I reguarly use 4.5 quarts) for better filtering preformance under higher pressures. What are your opinions on this? I don't really see how I can harm anything in doing so. I don't see myself changing to a synthetic for a motor which has already endured 126k miles with petroleum oils. So to summarize: What weight oil should I be using? 5W-30, 10W-30, or something else? (I'd prefer to use either the 5W-, or 10W-30 because they are recommened by the owner's manual, but I'm open to other opinions.) Also, what do you think about my choice of filter (PureONE) and would it be beneficial in changing to the extended length? (I would still be changing my oil every 3,000 or less). Thank you in advance for your insight.