M/T vs A/T MPG - Same Weight Tires

How much of a difference does the tire tread design make on gas mileage (if any) when comparing MT vs AT assuming the they weight the same? I have Cooper Evos MTs on now in 285/70/17 and they weight 53lbs which is on the lighter side for a E-load. I'm looking to get some ATs in C or E Load and and either keep the Evo MTs as dedicated offroad tires or to sell them. Main reason for wanting to go with ATs is that the tire noise from MTs is little too much for everyday driving. If the MPGs improve as well with the new ATs than that'll be a nice little bonus.

On another note the weight for Falken AT3W in C load is listed at 63lbs everywhere I looked. Is this a typo? At 63lbs the Falkens are heavier than most E loads.

Yet another odd spec. Toyo AT3 load C @ 55lb is heavier then load E OWL @ 53lb and it's the same as BSW @ 55lb.

 

Toyo confirmed that Load C and Load E BSW are indeed the same weight at 55lbs, and Load E OWL is lighter than than the other 2 because it is made in Japan and the rubber they use there is lighter than US rubber...

 

Yes, Falkens are bricks! The weight was one of the few downsides that made me not go with them.

I think the difference in fuel economy will be negligible if everything else is equal. I actually get similar fuel economy with 295/70/17 LT/E Yokohama Geolander MT's @ ~64# as I was with 285/70/17 LT/C Toyo AT3's @ ~55#.

Bear in mind that I do not drive aggressively so your results might be different.

 

Yeah if MPGs improve that would be cool but that's not the reason for the switch.
Since C and E loads for Toyos weigh the same choosing between the two is even harder now. $$ diff. between the two is negligible. When it comes to noise both should be the same. MPGs same. I suppose the Es would ride harsher on the streets but should be better when airing down and more resistant to punctures
Choices choices

 

My MT's are E rated and I have no complaints about ride quality. I think having a good aftermarket suspension helps a lot with this.

 

That's true. At this point i think it's between Toyo AT3 in E and General AT/X which only comes in E. Heard great things about both and either one should be quieter than the Evo M/Ts I got on now.

 

Look at 255/80R17 to get a weight reduction.
IIRC Falken AT3W had the lightest weight 255's.

Edit: Looks to 53lbs per Discount Tire.