1995 Geo Metro, 1 liter, 3 cyl., 156K miles. Went from 43 mpg best to 221 mpg and not yet dialed in fully, still testing! Needless to say, it is thus far a very BIG winner. Overkill for sure, wanted more capacity in order to be able to use generator on other 8 cylinder engines and power an HHO torch. With the Metro, the unit is idling, should last awhile, we shall see. At 20 amps setting, got 93 k on 1.03 liter of gasoline during most recent test drive. I burn premium fuel and measuring to within 1/10th of a liter for accuracy between fill ups. That fill up cost me $25.00 pesos, or $1.34 USD. I live in Baja, Mexico.We just ordered two more of these and one smaller one. Get them while it is still possible, a very good investment, yeah OGO!03-21-2023 updateUnit developed a leak not due to high temperature, I do not allow it to get too hot. One of the silicone gaskets blew out and drained all the electrolyte. Removed the unit and tried to tighten the finger loose nuts! Upon tightening them, many more gaskets popped out! Could not apply sufficient torque to seal the gaskets, sooo...................disassembled the entire unit, every part came out and was flushed, soaked, dried and reassembled. The dry surfaces of the silicone and SS caught well enough to apply a 10 in/ lb. evenly distributed torque. Unit reinstalled for the next test. CAUTION: before installing this device, make sure to test all the bolts and nuts for torque and equal distribution. KOH is very slippery and once a surface is wetted with it, nothing will grip to it, just slides around. I did not, but maybe apply some red or blue Locktight to the bolt threads before installing it.