strictly for summer

[mgrych]

My 08 135i has all the usual performance mods (assuming about 380-400RWHP) and I was wondering if I should run a thicker oil since I only drive it in the summer time and with the added mods.. Throw some ideas at me, and suggestions if you have any..

[Iron Man]

Originally Posted by mgrych

My 08 135i has all the usual performance mods (assuming about 380-400RWHP) and I was wondering if I should run a thicker oil since I only drive it in the summer time and with the added mods.. Throw some ideas at me, and suggestions if you have any..

No. Only use the oil viscosity(s) that are approved by BMW for your engine. A modern engine can use the same viscosity year round. For best start-up wear, you want to use an oil with a high VI, like Mobil 1 0W-40.