As stated by others i also think this depends on how the 30 minutes drive is spend to really get and maintain the oil up to temp.
A 30 minute city drive is not really enough. A 30 minute highway drive at 70 80mph+ does the job.
Then the question raises how many times do you plan to do it? Once every OCI, once a month, once a week?
To be honest i think that if a vehicle really sees every day short trips(severe service) it should be done atleast once a week or 2 weeks.
My personal 2005 bmw 325i sees 100 120mph daily commute back and forward for 50miles and i never have condensation problems or moist in the engine/filler cap.
However last winter i had a project for which i took a few weeks of and rented a storage unit nearby. I comuted to it daily by car. Its about 1 mile.
The N52 series bmw engines are known for creating lifter tick, i never had this problem in 100k miles of owner ship. However now i had this already after 3 days. First i thought it had devoleped an engine knock thats how bad it sounded.
I had to drive atleast 15 miles and pull it to the 7000rpm redline to solve this again. Has something to do with the hydraulic tappet oil canal not bleeding correctly because the car does not see above 2200 rpm on such a short slow drive.
Also after 2 3 weeks i could see condensation sludge forming on the inside of the oil filler cap, this also went away after my daily comute restarted again.
All in all it shows how my engine did not really like the (extremely) short trips instead of the fast highway routine. Somehow most people think that driving a car at that speeds daily is asking for breaking it but i have been doing this for 100.000miles now. I personaly think the short trips are the real killers for engines and have seen this happening multiple times as i used to own a car salvage business.
Low milage cars had the ****iest engines which fetched the best money.
High milage highway only cars had engines like new under the valve cover and went for 1/3rd of the price of a low milage engine.
Thats why i think its stupid that we still count cars at miles and not at operating hours like, planes, boats, generators, machines, tractors, basicly everything else except cars and trucks.
I'd rather own a car which spent 200k miles and for example 8500 hours on mostly highway instead of spending 2 times as much on a car which spend 60k miles but also 8500 hours bumper to bumper in traffic around the city.
