jake1829 119 Report post Posted October 22, 2014 Hi Was wondering if anyone could give me recommendations/advice for the oil I should be running on my 335i It's used as my Daily driver - doing avg about 60-80km/day and then the car is being used on the track - probably around once a month in summer - so around 8-9 times a year doing 10-15min sessions at hampton downs / taupo etc I am using the recommended oil 5W30 and changing it every 5,000k On the track, the oil temp is getting up to 140 degrees during those sessions, with the aftermarket oil cooler and thermostat - it pretty much stays there max and my own rule is if it gets to 145 , I'll get off the track and let the car cooldown (used to be a issue with the stock oil cooler) US forums - people are saying to run 5W40 / brands like Motul etc - was wondering the cons/benefits versus the 5W30 and if i should switch to a different brand etc Does anyone know what the track 135's here in NZ are running on their cars? thanks in advance Quote Share this post Link to post Share on other sites
yng_750 247 Report post Posted October 22, 2014 Basically a 5w40 will be a touch thicker than the 5w30 when hot. this will effectivly mean less pressure loss if it over heats as it has more viscosity to lose. Not sure about particular brands but sticking fully synthetic is a must on track at those temps. Most of those oils are rated for longer than 5k drain intervals but thats up to you if you want to spend a bit more and keep it cleaner by draining more often. Quote Share this post Link to post Share on other sites
