A note about 14v automotive Voltage Regulators
Since I found no reviews online about the HüCO Voltage Regulators before buying one as substitute for the OEM Bosch one, I figured I'd share my experience. - Bottom line: i've been very impressed with the huco regulator over Bosch and Transpo adjustable (IPD and Dave Barton). Excellent electrical performance with $12-$50 savings under heavy load.
First my complaint with the stock Bosch regulator. In the winter, at ambient temperatures below 50 degrees, the Bosch regulator put out a pretty stable voltage of 13.5 - 14.1 volts. Couple this with stock halogen headlights and lighting all around, plus the heavy demand of an 1800 watt stereo system and my average output at the alternator to recharge 2 batteries was around 13.5 volts. Add to this Air Conditioning and windshield wipers on a warm rainy night and pretty soon it's almost as though I have no alternator at all. To have to forfeit my music in the name of safety on a long drive is criminal.
Having upgraded many things including the lighting all around to custom made LED arrays and 4500k HID lighting in e-code headlamp in an attempt to diminish the overall load on the electrical system while making everything much more reliable - since most of my driving is by choice at night. The Bosch regulator seemed to be a little happier, emphasis on 'little'. So I eagerly tried two of the adjustable voltage regulators one available from IPD (internal regulator - this one had a major issue delivering even 13v under basic circumstances), and the other from Dave Barton (external fender mounted) - both were label-less Transpo brand. They DID live up to their promise in terms of voltage adjustability, yet couldn't keep up with demand once headlights were on and stereo going. Like the Bosch regulator, very slow response time and high susceptibility to heat leading to an exponential degradation of power stability sometimes having to adjust to the 15 volt point to get a steady 13.8, which is dangerous to any other electrical systems such as ECU. having spent $150 on regulators, including a new Bosch, I finally conceded and tried the aftermarket Hüco Voltage Regulator available at FCP Groton.
Success! 2 years running, and the Huco regulator has provided a steady and clean 13.9 - 14.2 volts on average with heavy load - everything in the car turned on (sometimes peaking at 14.7 on a very cold day, and occasionally briefly dipping to 13.6 before catching up). It was the answer on top of being $12 cheaper than the Bosch (fcp groton, much higher savings from auto store prices), and $30 savings over the adjustable ones.