Yes Top Tier gas does make a difference in your vehicle.
The Top Tier gasoline helps to clean carbon deposits off the engines valves and and pistons which helps improve engine performance.
In the old days it was recommended to remove the engine heads every 30,000 miles or so and clean off all the carbon deposits from the engine head and engine valves.
However now it's hard to do that and not needed as the Top Tier Gasoline can help clean those carbon deposits.
Also using fuel additives can also help clean the carbon deposits as well.
I use Top Tier Gasoline when I can get it and other times I may have to use regular gasoline which is also okay but I try to use Top Tier gasoline the most often.
My fuel mileage always improves when I do use Top Tier Gasoline instead of regular gasoline.
Top Tier gasoline is good for your vehicle and can help extend the life of your engine as it helps to clean the valves and pistons and removes carbon deposits.
Running Top Tier gasoline in your vehicle helps remove those carbon deposits which in turn helps improve your fuel mileage.
Your engine performance will be much better as well.
If the gasoline is Top Tier gasoline their should be a sticker on the gas pump saying that the gasoline is indeed Top Tier gasoline.