I have the Tel-tru's too. Oil temp may be a bit
behind (and higher than) water temp, but you should know when to start looking (hot day, slow/stopped traffic).
Couple things. They replace the dip, and have a line but I don't know if it's accurate, I always use the OE dip at oil changes (I don't know why I check, I have never burned or leaked a drop) (gallon out, gallon in, repeat every 6K miles).
It snugs down on an Oring so someone cannot just use fingers to walk away with it. You need to use a tool to snug and loosen it, if you turn it against force by the dial face, you will change the temp reading to inaccurate (which can be reset to 212* in boiling water).
The 2" gauge face is easier to read than the 1.75" face, but if you have the Kury tranny covers, the 2" face just touches the cover and will mark it (small). I have one of each on two bikes.
You should never have a heat issue at speed, but it can be a bit hard to see while riding (looking down) (you can see the sweep, but not read the temps) (I only wear single vision to ride, Varilux lenses in the bags). So I cut a sliver arrow shape of electrical tape and stuck it over the 220 mark on the gauge face (which is where you need to start paying attention), so when looking down, as long as the gauge sweep is below the 220 benchmark, you are fine. Mostly, you will be looking down at lights or stuck in traffic and is then easier to read.
I remember reading old threads here where folks tapped into the cooling system for water temps, and the debate was about doing that where the water was hottest (water entering not exiting the radiator).
Mine do not sit this high on the adapter.
