Can the gauge of the fuel line affect the gas milage of my car? on 1994 Toyota Celica

I had to have two fuel lines replaced because they were leaking. Now my mpg has dropped. I use to get about 400 miles per full tank of gas now I'm barely getting 300. I took a look at the gas lines and noticed they are fatter than my originals. The place that did the repair said the size wouldn't make a difference to my mpg.

Asked by for the 1994 Toyota Celica
No connection between mpg and line size! Lot of difference in fuel from one station to the next! Recheck mileage. Running ok?
Runs good.

Thank you for clearing that up for me. I'm going to re-check the milage.
Is there anything else that could cause a drop in mpg?
Not leaking is it? Tune up and check air filter. Some gas is just better than other.
There's no leaking. Thanks for the advice.
You bet!
1 more answer
wetry is right about fuel from station to station. tune up is good idea. give you chance to examine ignition cables. also look at tire pressure, wheel alignment, brakes and suspension. all of these can effect on road momentum in turn effecting fuel economy. prob. wouldn't hurt to clean fuel system with ethanol treatment to fuel tank. could be build up in fuel delivery.