Engine oil

QI own a 2002 Vauxhall Vectra estate 1.8 petrol, non-turbo, engine code Z18XE. I have owned the Vectra since October 2004 when it had 24,000 miles on the clock. I have changed the engine oil every 5000 miles (service schedule was either 8000 or 10,000, I thought they were a bit too much back then) with 10W-40.

Fast forward, the car is now approaching its next oil change at 235,000 miles and the engine still pulls really well and doesn’t use hardly any oil, less than half a litre a year – as the engine is getting older and obviously wearing – is there a better oil to use for this engine?

I know the Vauxhall and Auto databases for this engine recommend 5W-30, but I insist on 10W-40 if a garage does the job.

With a worn/wearing engine do you need/use a thicker viscosity oil? When I do my oil changes, I always use a Wynn’s oil flush additive and drain the oil hot/warm.

The car is still my daily driver. All advice and guidance greatly received.

Rob Thomas

AThe longevity and reliability of the engine is indeed a testament to the importance you have placed on the oil change regime. It is a fact that the oils available today are greatly advanced from earlier oils, and as such the included additives are also more effective in suppressing wear and suspending harmful particles. This is one of the reasons that the lower viscosity oils such as the 5W-30 are now recommended. One of the driving forces behind the use of the lower viscosity oils is the fuel consumption figures, and these oils can help improve the mpg of the vehicle.

The oil you are using is a good choice on your Vectra for the engine which has covered 235,000 miles and the only alternative I would recommend would be going to a 10W-50 semi-synthetic which will give that slightly heavier viscosity at the higher temperatures.

Other than this I would say that your current oil change interval is certainly helping to reduce the wear on the moving parts and has had a great influence on the longevity of the engine.

Whilst the action offered by the Alfa garage of having the software updated and the gearbox clutches recalibrated may be of benefit, I would want a more detailed report from the garage before going any further. If they are specialist in the TCT gearbox, then they should be acquainted with the codes and the reason for the problem – and should be slightly more confident on the actions needed to resolve the problem.

There are a few garages around who are competent to work on the TCT gearbox and finding one close enough will depend on your location. If not already done so I would join the www.alfaowner.com community and get a recommendation from one of the members – you will find a large number of threads in which the TCT gearbox is discussed.