did you change to ... I assume a high quality belt like a Top Cog by Dayco or the Green Stripe by Gates ? That's what I use, a Green Stripe 1/2" cogged belt. With the HO Alt, I easily get 500 hours and then I change it. I'm thinking I should just change it every year to be safe, with the 125A HO Alt, $15 of insurance is probably worth it. One of these days I'd like to upgrade to serp belt & pulleys ... that would be really nice, no more dust !
And WHY are you doubling fuel consumption ?
Cheers, John