Do Lighter Wheels/Tires and Smaller Diameter Wheels/Tires Improve Gas Mileage?

I recently bought new wheels and tires for my MK7 GTI. I previously had 19” wheels on my car, in these specifications:

Wheels: Rotiform KPS 19x8.5 ET45 5x112
Tires: Barum Bravuris 5hm’s 245/40 19

My new wheel and tire setup specifications:

Wheels: OZ Ultralegerra HLT 18x8 ET45 5x112
Tires: Firestone Firehawk Indy 500’s 225/45 18

Going from my 19” wheels/tires, to my 18” wheels/tires, I have saved 4.2lb’s per wheel/tire.

So I did a bit of a non-scientific mpg comparison from old setup to new setup.

Hope you like this video.

[jamesmedina]

I dropped 11 lbs per corner going from heavy stock 18's to OZ Chronos 17's but they are a little less aero. Main change is more quickness. Many people can drop even more weight because some wheels are boat anchors.

[roymartinez]

Thats great man this cars if you dont step on them all the time will get you really good mpg's i have the hyperframs 17x8 with 245/45 and i been getting amazing fuel economy, my average is 350-380 miles per full tank my mpg average is 28.4 to 29.2 can't ask for more out of this car and im manual as well.

[TaylorPhase]

Dang 26 mpg. I’ll still with my 90 mpg in my modded Hyundai

[LostMoneyGarage]

Lol. Now I know why you so jealous of nicks tuning. Ahahahahah