The Pico 2000 looks like a nice deal at $150. Four channel is good if you need to look at four signals at once. Need usually means they are interacting and related so you have to check syncing. Like a sensor input for a particular actuator output. Or parallel logic signals. Rarely do I need four channels. I use a RIGOL 1054 which is also very cheap. It has four channels but I never use all of them.

Most of the electronics I work on is one input and one output. You put the sensor input on channel 1 and look at the amp output on channel 2 and check their relationship. And even that, you probably only need to check one channel at a time to diagnose a fault. Two channel is good if you want to see the exact input level the amp is switching the output at. Good if you want to establish a connection between cause end effect. So I say four channels if you are working on engineering and you’re studying synchronous interactions between four signals. Two for doing basic diagnostics.

The second thing I’d look into is how good the software is on the pico scope. Software will make or break this thing. It’s pretty hard to get the hardware wrong on something like that but the software can make it either a joy or horror to work on. Check forums where people review the thing like EEVblog. You want the opinion of people who actually use it.

The last issue with these things is system upgrades. That’s the Achilles heel of PC instruments. You upgrade your pc and OS and your scope becomes a brick. I literally have win98 machines I keep to run old tools I got in 1998. It becomes quite a pile of laptops.

I guess the second issue about this stuff is how you’ll use it. Balancing a laptop on an air cleaner while a car is running is a hassle. Running cables around the engine is a hassle. Having too many dongles to keep track of is a hassle. My personal opinion is pc based stuff works well on the bench. In a rough environment I like self encapsulated things like armored scopes and meters. Although while doing field service it is easier to bring a usb device since I already may have a laptop. They’re really good like a Swiss Army knife - it’s good to have in your pocket just in case but if you have to use it regularly it is better to have a dedicated screwdriver, saw, knife etc.

Ok those are my opinions. I don’t use a scope much on the diesel cars. I guess I look at tach signals sometimes. It’s funny after spending my career on electronic design I choose to drive the most unelectronic car on the planet. It’s like an anti Tesla.

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79 300TD “Old Smokey” AKA “The Mistake” (SOLD)
82 240D stick shift 335k miles (SOLD)
82 300SD 300k miles
85 300D Turbodiesel 170k miles