As time goes on with 127000 miles on clock my vectra with it's 1.9 cdti 150 is starting to get a little bit of blue smoke on start up until I blip the throttle. Do you think by changing from 5w/30 full syn oil to 10w/40 semi syn oil little bit thicker will help with it's old age.
When I first got the car when it was 2 years old the service book said it had been on 10w/40 oil for the first 2 services then when I got it, I changed it to 5w/30 oil.
This oil any good of eBay as I change every 6 months.