I've owned a 2012 QX56 for a long time and like it a lot. But as we all know, gas mileage is abysmal. Does anyone have real world experience with any after market modifications that improve gas mileage at a reasonable price? I know that "reasonable" is subjective, but I'm interested in any recommendations.
This is a question every QX56 owner has probably asked themselves. The 5.6L V8 engine is powerful and reliable, but it is not designed for fuel efficiency. You're correct that it's an "inexact science," but here are some real-world considerations and modifications that can help, starting with the most effective and reasonable.
- Driving Habits: This is the most effective and cheapest "modification." Aggressive acceleration, hard braking, and high speeds are the biggest killers of fuel economy. Using cruise control on the highway and trying to drive smoothly and consistently will make a bigger difference than almost any aftermarket part.
- Maintenance: A well-maintained engine is an efficient engine. Simple things like having clean air filters, properly inflated tires, and a fresh oil change can improve your gas mileage. A clogged air filter can reduce airflow to the engine, causing it to burn more fuel.
Aftermarket Modifications:
- Cold Air Intake: This is a very popular and relatively inexpensive mod. A cold air intake replaces the factory air box and tubing with a less restrictive system. This allows the engine to pull in a greater volume of colder, denser air, which can improve combustion efficiency. This can give you a small increase in horsepower and a slight improvement in gas mileage, but it will also give you a louder engine sound.
- Cat-Back Exhaust System: A less restrictive exhaust system can help the engine "breathe" better. By allowing exhaust gases to exit the engine more quickly, it can improve efficiency. A cat-back system replaces the factory exhaust from the catalytic converters back to the muffler. This will also give you a more aggressive exhaust note.
- Performance Tuner or Chip: This is another popular option. A tuner can be plugged into the OBD-II port to optimize the engine's computer settings for better fuel efficiency. They can adjust parameters like ignition timing and the air/fuel mixture. These can be very effective, but you need to be sure you are getting a high-quality product from a reputable company.
Realistically, a large, heavy, V8-powered SUV like the QX56 isn't going to get great gas mileage no matter what you do. Aftermarket modifications can help, but they will likely only improve your fuel economy by like 1-2 MPG at most. The most significant gains will come from a combination of these modifications and a change in driving habits.
