Mrs. Jones Asks: Why does my book say change my oil at 8,000 Kms and my trusted repair shop is recommending it sooner at 6,000kms?   Mark Says: Well I find that the oil change interval (time and KMS) between oil changes in the book are great if you don't plan to keep your car after the warranty runs out. Why?   Well motor oil is the main lubricant and also a cleaner for you internal engine parts, and when oil is driven up to and over 8,000kms/ 6 months we find that deposits build up inside and can cause issues later on.   New technology in engine designs like:  Variable Valve Timing, Twin Cam overhead valves, Turbo Charging, Direct Fuel Injection, VCT transmission, Hybrid engines are all designed to give us:  more power, use less fuel, reduced tail pipe emissions; All rely on clean quality oil and filter, and maybe some help from additives.   Some of the Problems we see due to extended oil change intervals are: Engine slugging and deposits - repair cost $200-$5,000 Stretch timing chains - repair cost $1,000-$2,000 Sticking or clogged Variable valve timing solenoids - repair cost $500-$2,500 Damaged Turbo chargers - oil starvation due to clogged screens - repair cost $800-$5,000 So let's look at the true cost of replacing the oil a little sooner than the book says and help to avoid some of the above mentioned oil related issues: Let's assume you drive 25k a year, keep your car for 8 years or 200,000kms A basic oil change service costs about $40.00 + tax 25k/8,000km = 3 changes a year at $40 = $120 x 8 years = $960 in oil change service only for 200,000kms 25k/6,000km = 4 changes a year at $40 = $160 x 8 years = $1280 difference of $320 over 8 years 200,000kms So the cost over 8 years doing 1 extra service annually (shorter interval) is only about $320 for basic oil, sounds good eh? Like the old "Fram Oil Filter"  TV commercial, "pay me now Or pay me later" starts to make more sense now. Cheers, Mark At Mark's Auto Service, we know the importance of scheduled maintenance, including oil changes. You don't have to go to a quick stop or the dealer. Don't worry about your warranty, it's safe here at Mark's.