I've bought this van (GC 08' 3.3L) in May 2011 with 52,000km and now it has 56,000km. Previous owner changed oil (full synthetic) at 49,000km. Do I need to change it now ASAP?
I guess fully synthetic oil is the way to go? But I don't know the brand of the oil used previously (since I moved to another city - Toronto). Do I need to flash and re-flash oil with cheaper oil first and than change it to some good brand full synthetic oil (to avoid mixing oils of different brands)?

 

The owners manual on my 2010 GC (3.3l engine) recommends oil changes every 10,000km (on conventional oil) and seeing that you've only done 7,000km on synthetic, which lasts longer (up to 20,000km with some brands but I wouldn't even think about going anywhere near that) you should be fine. There are some who are old school and recommend every 5,000km on conventional but oil technology has improved to last longer. So the ultimate decision is yours. If you change it more often, you get better fuel economy, the engine will feel a little smoother and your engine will probably last longer. Personally on my van I split the difference and go around 7 or 8k between changes depending on how the oil looks on the dipstic. By the way the owner's manual doesn't call for synthetic so conventional oil is fine for warranty purposes even though synthetic does a better job lubricating and handles extreme temperatures better.

Never heard of having to "flash" oil and mixing brands is fine as long as you stick with a good brand name since these oils are manufactured to required specs. Some shops will try to sell you an "engine flush" to flush out all the old oil and any debris in it, but i recall the owner's manual says it's not necessary and could damage your engine, so I'd avoid it.

 

Thanks Marcus71 - I feel more confident now.