Winer Time oil (yes I searched the topic)

[E300D]

After reading many posts about oil etc...it seems like I still can't get my question answered. Here is the scenario:

car- 1995 E300D 167,000km, all of its life treated with non-synthetic 15W40 oil and 10W30 for winter by the previous owner.

The P.O. didnt really drive the car in winter. I will be driving the car in winter and the temp may dip to -20 C or more. I would like to minimize the cold start strains on the engine, starter etc...

Since we dont do any excesive driving etc... 65% city driving, I want to stick with the 5000km engine oil change intervals witht the 15W40 non-synthet.

For winter I want to use a synthetic oil due to better flow etc...

So, my question is:

Is it a safe practise to alternate between synthetic and non-sythetic oils?


(Like I said I searched the topic, but i could find any helpful info)


Thanks

[Hit Man X]

I'd stick with syn or dino, not alternate between the two. Syn will yield extended drain intervals and typically better protection.

Rotella Shell is ~$7/gal here for 15W40...