Mine uses about 3/4 of a quart of oil between fill ups (about 320 to 350 miles). It seems excess compared to other VX's, but that's the way it's always been so as long as I stay on top of it I'm not too worried.
As for your check engine light it could be a few things.  The easiest thing to check first is if your gas cap is on tight enough.  When you crank it down let it click a few times to make sure it's seated well.  If not, that could throw a CEL.  The other thing that I have noticed out here in Colorado is that I will get a CEL sometimes if I do big elevation gains or losses.  I don't think the computer likes the different oxygen readings that it gets so it throws a tantrum and turns the CEL on.  Could be that easy, but go to AutoZone and have them read the code for you.
				
			 
			
		 
			
				
			
			
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