Hey kids! Wanna convince Mom and Dad that the family sedan really needs that new high-flow exhaust you’ve been eyeing? It’s simple – tell ‘em it’ll help boost mileage and fuel efficiency! It’s true – performance upgrades like a new exhaust and water injection system not only add ponies, but increase mpg as well. And according to Autocar, that’s exactly the logic Bosch is using as it plans to install its water injection system on more models by 2019.