It last about four years on the Stratos, Flat 12. It starts the car easily and can be mounted in any position. It's a great battery, and the leakproof, non-corrosive characteristics are real plusses. The fans on my Dino (a 73 US model) seem to go on more frequently than on the Stratos, so I wonder whether the additional load would suit the Redtop. I have Redtop 30 on my Lotus Elan, too. They're not inexpensive, though.