We have a 2012 E350 RWD and are looking at a 2019 E300 4Matic. Have one picked out with 85k miles, initial test drive was okay, will be going back Monday to look at it more closely. Two questions:

1. What are common problems with the 2019 with the turbo I4?
2. As a decently-skilled shade-tree mechanic, how difficult are they to wrench on for routine maintenance (oil, brakes, spark plugs, alternator) compared to the 2012/W212? My wife's previous car (Audi A8) it was virtually impossible to do anything unless you had the USB-OBD2 module and special computer software. Couldn't even reset the oil life monitor or release the parking brake for rear brake pad changes.

 

I’ve done all the work on my E300 since I bought it back in September 2018 and if you’re handy and a DIY type you shouldn’t have any problem's at all. One tool you’ll want to have is a Jabsco oil change unit.
It’s a unit primarily used for changing oil on boat engines but it works perfectly when changing the oil on an E300. It draws out the old oil thru the cars oil dipstick tube and makes changing the oil a snap. If you’re buying a used car you can safely assume that the maintenance is Not up to date and doing the following things would be a good start.
1). Oil & filter change
2). Change engine air filter, change cabin intake air filter located just above the battery.
3). Check battery condition
4). Change all 4 spark plugs
5). Pull all wheels and check brake pad thickness as well as rotor thickness (rotor runout is 29.4mm).
These items are a good start at the minimum. Good luck.

 

The battery condition is a tough one IME. It may test OK but still be weak. If the battery in the new-to-you car is the OEM battery, I would go ahead and change it. You're lucky if you get 5 years out of these batteries. The batteries are actually far superior to the old Lead-Acid batteries all cars used to run on but the amount of electricity required in modern cars is a huge factor in their shorter lifespans.

 

I better switch my battery then soon. Believe it or not last week, I just hit 7 years in my OEM battery for a 2019 E300 4matic.

 

I'm on my second battery. We put less than 7k a year on ours so it sits for a while. I tried to use a trickle charger but it was tedious to use. On our Porsche I installed a permanent trickle charger connection port that easily is accessible when you open the trunk to connect to the charger and then allows you to completely close the hood once connected. I am able to leave it weeks at a time.

 

I have a MY2017 and still on my original battery. Car only has approximately 46K miles, however in the midst of COVID it was parked way more than it was driven. I have used a trickle charger since then if I don’t drive for a couple days. Not sure what’s tedious about using a trickle charger with only having to disconnect/reconnect the charging cables as needed.

 

Perhaps my garage is larger and the outlets aren't close by and I have to use the same outlet for multiple purposes? Any maybe my Porsche is kept at my vacation house that has a dedicated outlet for the trickle charger?

 

Fair enough, use a surge protector just as I do, or just keep replacing batteries.