New 2011 gmc Acadia SL owner - any tips/info on what the true 'full or semi- synthetic' oil change interval should be?

[ayarrington]

I have a 2011 Acadia Sl we just bought recently with just under 150K miles on it. The previous owner I bought it from wasn't able to provide me with any documentation from the last oil change, so I thought I should just get a fresh oil change and plan the scheduled oil changes going forward from there. After exhaustive research online, I decided to get a full synthetic oil change and it's scheduled for tomorrow. Now, their reminder email says the interval for when to do the next oil change is 7500 miles, but I'd swear I've read it is actually much longer. What would y'all say(especially from experience) should be the interval that I plan on, given that it will be a full synthetic oil, not conventional nor semi-synthetic? Thanks much in advance! Also, it's still possible that they'll actually use semi-synthetic, so pls keep that in mind and respond with the appropriate interval for the semi-synthetic, too...tks much in advance and please respond yet today......again, it's tomorrow morning that the oil change takes place...

 

[ayarrington]

I'd still welcome any tips or wisdom re: the replacement interval, but we did go ahead and get this done today and I believe they used semi-synthetic oil..