Ive learnt over the years to take what Holden says with a grain of salt. Their warranty isn't worth the paper it is written on. Maybe other people have a different opinion, I'm speaking from my own experience. Holden recommend I run 32 psi in my tyres. Do i? Hell no. Holden recommend I change my oil every 15000km. Do I? Hell no. Holden say I can run my car on E10. Do I? Hell no. Holden say I should put 5w 30 in my car. Do I? Hell no. Do I take my car to Holden for servicing? Hell no. I think you get my point. Just because they manufacture the car doesn't mean they are the be all and end all. Thats just what I think.