Electronic Octane Testers on eBay

[smonska]

So, for $115 you can buy an Octane Tester tool on eBay, seems like the kind of thing a nerdy engineer like me would buy for no valid reason.

Has anyone tried one, and if so how different are various stations' octanes? Most of my vehicles require 91, one (my Ram) takes 89. Would be neat to know if I'm getting what I pay for.

https://www.ebay.com/sch/i.html?_fr...TRS0&_nkw=octane+tester&_sacat=0

 

[sloinker]

Motor or RON ?

 

[eljefino]

I wonder if it needs any consumables to run, and/or how long the calibration will stick.

 

[ammolab]

It is from Russia, what could go wrong?

 

[y_p_w]

There are portable testers that are accurate and even used for mobile spot testing. Quite a few states have mobile labs that can do this sort of thing.

https://store.clarksonlab.com/K88600.aspx

Anyone want to spend $17,000 on one though?

 

[dishdude]

If you want to throwaway $115, I'll send you my address! haha

 

[Revving2Redline]

I sit on my octane tester in the car everyday. Granted its only able to sense non ethanol grades 87 to 104.

 

[kschachn]

Originally Posted by Marco620
I sit on my octane tester in the car everyday. Granted its only able to sense non ethanol grades 87 to 104.

I don't understand. The octane rating isn't dependent on the fuel composition like that, there are many ways to create an apparent octane rating. In that regard your engine can't tell the difference, as far as the knock sensors are concerned (or your ear) it doesn't matter whether the gasoline is straight iso-octane or contains MMT, toluene, tetraethyl lead or ethanol.

 

[y_p_w]

Originally Posted by kschachn
Originally Posted by Marco620
I sit on my octane tester in the car everyday. Granted its only able to sense non ethanol grades 87 to 104.

I don't understand. The octane rating isn't dependent on the fuel composition like that, there are many ways to create an apparent octane rating. In that regard your engine can't tell the difference, as far as the knock sensors are concerned (or your ear) it doesn't matter whether the gasoline is straight iso-octane or contains MMT, toluene, tetraethyl lead or ethanol.

Sounds like a "butt dyno" joke really.

I thought that the practical way would be to test in an engine against a fuel made with iso-octane and n-heptane. But with that the limit is 100% iso-octane as the reference.

I remember hearing about octane rating rigs that use variable compression ratio engines to test higher than 100 octane. Something like this:

 

[Dinoburner]

How would one calibrate such a device?

 

[kschachn]

Originally Posted by y_p_w
I thought that the practical way would be to test in an engine against a fuel made with iso-octane and n-heptane. But with that the limit is 100% iso-octane as the reference.

I remember hearing about octane rating rigs that use variable compression ratio engines to test higher than 100 octane. Something like this:

I took a fuels and lubricants class in college and that one looks similar to the one we used.

 

[smonska]

Found a few videos online about this model of tester, apparently they don't function if there is ANY ethanol in the fuel, will just read "110". Here in Massachusetts, all gas is E10, so this device wouldn't be practically useful for me in any way. I'd have to drive to New Hampshire for 91 non-ethanol, at an extra $1/gal.