Did some searching here and didn't turn up much.

Any recommendations for the good bluetooth OBDII dongle from the dozens of options on Amazon?

I have a wired one. I want to go bluetooth to more conveniconveniently get live data.

 

I have this and it works. I don't think the actual readers have limitations, it's the software that queries them, on your phone, that may need Mazda-specific code libraries. I think in Torque you have to buy the Mazda package. But that's only important if you have a Mazda-specific problem like the OMP, and have a check engine light but the reader shows no codes.

 

I have a similar to this one I bought many years ago, I use it with Dash Command. All of them work ok if you are just collecting data, reading codes or just use it for monitoring, but would stay away from any type of programing, or uploading.

 

I use Torque pro (paid version) and no need to purchase Mazda specific package, nor even download it. I can confirm that it will read OMP codes also.
Its one of the early ELM327 Bluetooth readers that I have had for years, and yes it's blue in colour. From memory I bought it off eBay. No idea of brand it has been used in multiple vehicles.

 

I have this one and it works well. Very nice user interface and seems to be quite reliable.

 

I went with this one because it had a coupon and I had enough Amazon gift cards to cover it outright. If it fails to perform like I want I'll put it in my truck's tool kit and try something else.

 

This should/ could work fine. Some of the different phone apps are rubbish, both free and paid. As above i would highly recommend the free Torque app. The paid one is better of course and i upgraded after about a year.
Be warned the cheap dongles sometimes just dont work, often they will though so worth a shot. Good luck.

 

Already have Torque free installed and will upgrade in the future perhaps. If the dongle arrives DOA Amazon returns are easy.

My main goal is to watch coolant temp. My gauge in the dash isn't indicating any issue but I'm still a bit shocked at how much heat this car generates so I want to really make sure I'm keeping it cool.

 

Like many here i just use an old android mobile strategically placed on front screen for gauge purposes only. I dont even bother with a cord as a single charge will go for the day.
I'll try to find a sreenshot of the ones i use and put them here.

 

This screenshot was about the only time i have ever seen both long and short term fuel trims at zero at same time. This setup works well for me.

 

I used this with "car scanner" app. I was able to read and clear error codes as well on my 09 S2 - R3.

 

^^^ I think that's the same one I've had for years, works great with the Torque app as well.

 

That is the same one I have. Don't know if it will read all of the Series II potential outputs though.

 

I think the code reading is up to the software you're using with it.

 

OBD bluetooth scanner:
OBD app: https://www.obdsoftware.net/software/obdfusion

Make sure you unplug your bluetooth scanner because it will continue to drain your battery. Some models are smart to turn off automatically. Mine doesn't.

 

I use Torque light and DashCommand. I even overlay a video with data from DC a few years back

 

I have a "ThinkCar 2" OBD which is pretty damn good considering the price. Will scan every module your standard car has based on the VIN.