10/06/2026
Have not updated in awhile on our 2021 3.0 duramax suburban we started out with it 100% stock and added a cold air intake, the mileage actually dropped from what we could tell in the 10,000 miles we drove it. We have now added a ppe air to water what an improvement with both cold air and the air to water. Mileage is back up to 26 mpg now, we will see if it keeps going up we are getting quiet familiar with these if anyone has questions or needs some up grades done let us know.