I consistently get 27 mpg in normal weather, but on my last tank i only got about 21 mpg. The only difference i can think of is the fact that it's been in the negative teens (farenheit) lately compared to the positive twenties that it's been the rest of the winter. I've even been driving w/ less throttle to warm up the engine slower in the really cold weather. should i be worried about this sudden change?

 

I would think it was because you are pulling alot more air since it is cold and also more fuel in the cold....i wouldn't worry

 

nope.. cold (denser) air needs the fuel to match..