I have replaced all (100%) of the incandescent bulbs of my 1995 Buick Regal to LEDs (including the headlamps and every single interior and exterior lamp) in 2010, and it isn't a cost saver. It does make the car more visible at night and during our rainy seasons, so it increases the safety feature and prevents accidents due to poor atmospheric illumination. That is worth the cost! The second benefit is that it will never need any bulb replacements under normal use for the life of the car. I sold the Regal in December 2015 (I had it since December 1994), so it is still running after my 21 years of ownership. The new owner loves the Regal, and really appreciates the higher visibility.
Last menth (February) I completed the 100% replacement of all the lights in my present 2009 Chevy Equinox (also the headlights and every interior and exterior lamp), and it is much more visible even with the DRL on. I am happy with the cost and work investment, and it will help protect me and my wife from possible accidents due to poor illumination, too. So this is a added safety issue for me, and will not save money in gasoline.
All my LEDs were purchased from one distributor, Formula-J87 (http://formulaj87.com/) and they will sell a set according to the vehicle you have, including the two generations of the Chevy Volt. They sell great brands, not the cheap Chinese knockoffs, and offer a warranty on any products. One of the red tail LEDs for my Regal was a DOA, and they sent me a replacement. I found them at eBay and bought my Regal lamps this way, but now I buy directly from their store. Here are their eBay reviews:
https://www.marketplacepulse.com/ebay/usa/formula-j87
http://www.ebay.com/usr/formula-j87?_trksid=p2053788.m1543.l2754
Last menth (February) I completed the 100% replacement of all the lights in my present 2009 Chevy Equinox (also the headlights and every interior and exterior lamp), and it is much more visible even with the DRL on. I am happy with the cost and work investment, and it will help protect me and my wife from possible accidents due to poor illumination, too. So this is a added safety issue for me, and will not save money in gasoline.
All my LEDs were purchased from one distributor, Formula-J87 (http://formulaj87.com/) and they will sell a set according to the vehicle you have, including the two generations of the Chevy Volt. They sell great brands, not the cheap Chinese knockoffs, and offer a warranty on any products. One of the red tail LEDs for my Regal was a DOA, and they sent me a replacement. I found them at eBay and bought my Regal lamps this way, but now I buy directly from their store. Here are their eBay reviews:
https://www.marketplacepulse.com/ebay/usa/formula-j87
http://www.ebay.com/usr/formula-j87?_trksid=p2053788.m1543.l2754