N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
There are too many variables between two people in different locations to make that comparison. Overall, I don't think wheel weight has a big effect on economy. Personally, I dropped 6.5 lb per corner and I don't believe I gained any fuel economy from it. The fuel economy differences between different tires is well known though.