📋 Quick Facts
Highway loss
0.5-1 MPG
City impact
Negligible
Power-deploy
+5-10 lbs vs fixed
Tubular vs flat
Tubular slightly worse
Running boards typically cost 0-1 MPG on the highway through added aerodynamic drag. Power-deploy boards (AMP Research) cost slightly more than fixed boards because of added weight (35-50 lbs per side).
Where the MPG goes
- Aero drag below the rocker panel. Even though running boards sit low, they disturb the underbody airflow that modern trucks are designed to manage.
- Weight. A pair of aluminum fixed boards adds 40-60 lbs. Power-deploy adds 80-100 lbs.
- Tubular boards with open shapes (Westin, N-Fab) create more turbulence than flat OEM-style boards.
Real owner-reported numbers
- Ford F-150 5.0: 0.4 MPG average drop highway with AMP Research power steps.
- RAM 1500: 0.5 MPG drop with N-Fab Wheel-2-Wheel tubular steps.
- Tahoe: 0.3 MPG drop with OEM-style fixed boards.
When to skip running boards
- If MPG matters more than easy entry, leave them off. The aero penalty is small but real.
- If you live in snow country, fixed boards are mud traps. Power-deploy tucks out of the way.
- If you tow heavy, the added weight matters - boards reduce payload capacity by 50-100 lbs.
🔗 Related Guides
❓ Frequently Asked Questions
Are flat boards better than tubular for MPG?
Marginally - flat boards (OEM-style) disrupt underbody airflow less than open tubular bars.
Do power-deploy boards hurt MPG more?
Yes - by 0.2-0.4 MPG more than fixed boards because of the extra weight and slightly worse aero in the stowed position.
Will I gain MPG by removing factory running boards?
Possibly 0.3-0.5 MPG on the highway. Most owners cannot detect the change.
Does N-Fab vs Westin make a difference?
Aerodynamically, no measurable difference. Build quality and finish are the real differentiators.
What about rock-rail style step bars?
Heavier than running boards, similar aero impact. Worth it for off-road protection, not for MPG.
Will the dealer mind running boards on warranty?
No. They are bolted to factory mounting points and do not touch the powertrain.