Any oil has a limited life. Better oils generally last significantly longer than cheap ones, and give better protection and performance. But it's better to change a cheap oil often than leave a high quality one in for a long time. I'd say no more than £4,000 miles between changes. Remember that prevention is significantly cheaper than cure when it comes to 300ZX's and an oil change costs peanuts by 300ZX standards.

 

Time, temperature and use(no. miles driven and driving style) affect the life of an oil. So Twin Turbo cars in particular with high engine temperatures need more frequent oil changes (at least twice as often as a regular car).

 

Oils age much faster under cold [winter], short trip driving because the engine and oil never get very hot and this doesn't drive off water from combustion and this results in acid build-up which degrades oil fast. So change oil in early spring. Best conditions for oils are long trips in the summer. So good to change oil in late autumn before winter.

 

Also - important to not switch engine off immediately after stopping, especially after long trips or after driving the engine hard as the oil around the turbo shafts will be very hot and you need to dissipate this heat [allow cooler oil to be pumped around it] to prevent coking and turbo's from seizing.

 

Many of you will know this, but useful for those that don't. The cause of many or most turbo's blowing is probably the result of insufficient oil changes.

Good advise there, oil change`s should be viewed as money in the bank reliability wise.

 

As an addition to previous information: sump plug is 14mm and always fit a new washer

 

Nissan filter is part No A5208-H8904

Nissan sump washer part No 11026-01M02

 

Oil choice is maybe a personal preference but use a semi synthetic either a 10w 40 or a 15w 40. which give`s good protection when hot and a easy starting.

 

Castrol Magnetec

Millers (semi synth)

Shell Helix

 

As a final point be careful to not overfill the sump as the dipstick is very inaccurate 3.5L to 4.0 litres is max as the coller and associated pipework will not drain unless disconnected aim at about 1/3 below the HIGH mark and LOW mark on the dipstick

 

 

Jeff TT

 

 

 

[This message has been edited by Jeff TT (edited 08-07-2002).]

Jeff,

 

If the sump is a little overfull could that lead to oil being sucked into the left turbo /exhaust and burning to give smoke on occasions? And would it lead to an oily smell wafting thru open windows when driving?

 

Cheerz

Coogs, quite possible have seen a few cases of smoking caused by overfilling where also the breather system may need attention (Pcv valves) when changing the oil do not make it a mission to get all the can in! after a normal drain I would say it possible that up to a litre of old oil can remain in the engine, cooler and pipe`s etc, so adding another 3.5 to 4 litre`s is over full. When refilling add 3.5 litre`s and then run the engine for a few minutes ,wait for a few minutes again and check the level, be cautious, and only add oil in small amount`s till slightly under the HIGH mark

 

Jeff TT

 

 

[This message has been edited by Jeff TT (edited 08-07-2002).]