I've taken a lot of heat over my opinion about the difference between a 135 CCA battery and a 210 CCA battery, none the less let me repeat -- if a brand promotes a 210 CCA battery, compare its weight to the 10.1 lb 135 CCA battery. If the weights aren't significantly different the battery vendor is playing a spec game about how CCA is measured. To have higher CCA the battery must weigh more. Just because the battery industry has a standard on how to measure CCA doesn't mean that a company may 'free lance' a bit and be liberal in how they advertise the capability of their batteries.