Fully synthetic oil?

[Jamesstone]

Well my little clio mk2 1.2 is going in for a minor service this weekend, i've got a m8 who's gonna do all the work as he's a mechanic at bmw so he can put it up on a ramp & do it in no time compared to sitting on the drive way.. basically i went out to look at the price of oils & for castrol 10w40 semi synthetic its gonna cost around £25 so i let my m8 know & he said they use castrol fullysynthetic 0w30 on the cars there & could get me 4l for £22 ( staff discount ) so my question is would using a thin oil on a car thats probarbly ran no better than 10w40 for 65,000 miles course problems? surely if anything it should see benefits from using good oil but i don't want the car to start blowing smoke or anything like that so just thought i'd see what you guys think

James

 

[cli0 172]

i'm no expert at oil but i wouldn't see the point at going for 0w30 ,it may be fine ,i'm sure someone with a better knowledge will answer soon .

people on here put 5w40 in their 172/182's