Since I had my Alternator replaced I have noticed a decease in gas mileage by 1 mile a gallon. I have 5500 miles on my MO and I was hoping it would improve. As it was I was only getting 15.6 miles to the gallon with short trips and a lot of stop in go driving. Now I am down to 14 miles to the gallon. Could the more powerful Alternator cause a decrease in gas mileage?