It pretty accurate! As soon as I received the item I dipped the sensor into a kettle with cold water and wait till water gets boiled... Temp raised till 99 degree C...(supposed to be 100 C as a boiling point). But I think +- 1degree C is accurate enough for engine temp! Next step install this inside my Ford Fiesta cause it doesn't have temp gauge from the factory.

Satisfied with this purchase so far but I'm interested to see how long it'll last.Installed the 18mm version on my 2013 650 Brute Force SRA.I cut the rear cylinder coolant return line and installed the sensor. Connected the power leads to the wiring for the 12V auxiliary plug. All in all, other than the need to top up the coolant afterwards, installation was easy. Maybe took an hour. Power lead was long enough for my application but may be short if you're going to the battery or fusebox.Can't say how accurate it is because I have no means to compare with another thermometer. I installed this because I wanted to have some redundancy for my high temperature light in case it fails, so to prevent overheating.Subtracted 1 star because it fastens to the mounting bracket with 2-sided tape.

I have had this on my V-twin motorcycle for two weeks now and 800 miles worth of riding.I got lazy and installed the temperature probe in the most visible and accessible radiator hose I could find-- the one at the bottom of my radiator, bringing the cooled liquid back to the water pump underneath the engine.This means, of course, that if my water pump stops working or my thermostat never opens, the water where my new sensor is will be artificially low, whereas the water that comes directly off the engine heads could be too hot (this top-end area is where the factory put its water over-temp warning light; right below the T-stat).Anyhow, the placement of my temp-sensor had the effect of giving me a few minutes' warning that my bike was about to overheat this past Monday. After hours of highway riding when the temp shown was about 85 C, it suddenly dropped through the 70's and 60's and into the 50's Celsius. That puzzled me at first, then I realized that this meant that the temp probe was no longer bathed in a flow of hot water, and it was instead surrounded by air. Air that was being cooled through the wind hitting the outside of that radiator pipe. 75 MPH wind, as rode down the interstate on a day when the outside air temp was around 30 Celsius.Sure enough, a minute later my factory red over-temp warning light came on.I had a radiator leak and had lost about 1/3 of my radiator's capacity. A pint or so of coolant added, alongside the road, had me back to riding the rest of the day.Wiring this device was easy, but time-consuming. There is a wire going down to the radiator hose to tell the display unit what numbers to show you. THen you need to run wires to the battery or other source for power to light up the display unit. I chose to go right next to the battery and use a quick-connect pigtail (SAE) that fits the quick-disconnect fitting for my battery tender. This means that my water temp display will not shut off when I turn the ignition off or take the key out; it will remain on when I'm parked, unless I disconnect the SAE pigtail connection. That's fine with me. I'll let the unit display my coolant temperature all day, any day I'm using the bike. But for overnight parking I'll go through the effort of pulling the plug. If I wanted to put in extra effort, I suppose I could have installed a lighted 10-amp switch inline on the positive side (well, a lighted switch would also require a ground).This unit seems accurate at the low end of its range, because when the bike is cold, parked in the garage overnight, the temp displayed for my in-radiator temperature matches the air temp in my garage as shown by two other thermometers. I have no way of comparing the "hot and running" temperature readings to anything else on my bike. But the numbers (for post-radiator coolant that's just passed through the radiator from top to bottom) seem reasonable and well within what I would expect.ONE THING about MOUNTING this unit: It comes with sticky tape to mount it to a clean flat surface.There is no such surface on my motorcycle. Maybe the fuel tank, but I wanted the gauge / display unit mounted up on my 1" diameter handlebar. So I fabricated a flat wooden mounting surface, clamped and screwed to my handlebar, on which I glued this coolant temperature gauge. It's a permanent mount, not easily removeable without destroying it, but for under $20 I didn't care. It seems to work fine and I'll leave this gauge in place for the rest of this motorcycle's working life. But if you are installing this unit on a car with a dashboard, the installation should be even easier if you have a flat, clean dash panel to mount the display unit to.

La valeur de température est fausse de 10°CJe l'ai testé dans de l'eau avec un autre thermomètre classiquele thermomètre classique affiche 15°C et le numérique affiche 25°CJ'ai donc comparé avec un thermomètre laser qui m'a affiché 15°C égalementJ'en conclus donc que la mesure de l'eau n'est pas fiable avec ce thermomètre et donc je ne recommande pas ce produit

I put it on a 300 cc scooter and has not failed me

Annoyed with myself for not understanding description which says 12v.The photo shows a unit that does not have a live feed cable....not true...it has a second cable.(I thought it had it's own battery)

Easy to install works great. I love knowing the temp od my atv. I put it on a 2013 Polaris sportsman 500ho.