Update on the fairing after a 9500 mile road trip:
TL;DR - larger, lower-angled fairing is better
I just got back from a 7 week, 24 state, 9500 mile road trip with TRuDy. Overall I used 476.75 gallons of gas giving me total average MPG of 19.926 miles per gallon.
Throughout the trip I had several tanks where I got 22.5 MPG, and a couple where I only got 16.5 MPG. I only used regular fuel with no more than 10% ethanol, usually sourced via the GasBuddy app to save $$. Highest I paid was $4.299/gal (Oregon) and lowest I paid was $2.799/gal (Tennessee) although I did see some stations selling for over $5/gal in the Chicago area and rural Washington state.
The higher MPGs I found were mostly at highway speeds between about 60 and 70 MPH, or on back roads doing around 45-55 MPH. Anything higher than 70 MPH and the gas mileage really dropped off fast (one tank that got 16.5 MPG was doing 76 MPH across South Dakota).
Since there are a million factors that can effect gas mileage (outside temperature, elevation, tire pressure, road surface, flat vs. hilly/mountainous roads, running the air conditioning, headwind vs. tailwind, humidity, traffic, etc.) I don’t have a magic formula for the ideal sweet spot, but based on my non-scientific observations, I’d say the fairing was worth the investment.
My general takeaways are:
- Highway speeds below 70 MPH give better MPG
- Flat terrain is generally better than hilly/mountainous terrain, but winds can have a huge effect either way.
- The cruise control liked to run at a higher RPM to keep the speed within a much narrower range whereas if I allowed the truck to slow a little more on uphill sections and speed up a little more on downhill sections I got much better gas mileage. I only did this when the traffic allowed, but it made a difference.
- I rarely ran the air conditioner unless the temp was over 90*F so I don’t have a good read on how much it affected the gas mileage. Usually I had the back cab window open and the front driver and passenger windows cracked. Before the GFC I almost always did this and the air flow was great. With the GFC on before the fairing the air flow was greatly reduced in this configuration. With the fairing, the air flow is much better and the noise has been reduced with the back window open.
- I don’t idle my truck if I can help it. If I’m parked, I turn it off. This obviously contributes to better gas mileage.
- I removed my 2 beef bars for this trip since I wasn’t going to be using them. The weight and drag reduction probably helped the gas mileage as well.
- I was loaded up for a marathon vacation on this trip. Probably around 200-250 lbs of gear throughout the truck (mtn bike, fridge, aux battery, bedding, cooking stuff, clothing, shoes, water, etc). Without this added weight I probably would have had slightly better gas mileage.
I can’t directly compare this large fairing to the much smaller one I originally had on from Front Runner, but in my observations the big one is quieter and all indications are that it has improved gas mileage.
If I remember correctly, pre-GFC I usually got about 22-23 MPG on average in the warmer months and 20-21 MPG on average in the colder months. This was mostly commuting to work (45-55 MPH on country roads through corn fields in rural NJ) and running errands. After the GFC was installed I got about 20.5-21.5 MPG on average in the warmer months and 19-20 MPG on average in the colder months. With the new fairing I haven’t had enough time replicating that commute to make a definitive assessment (starting a new job next week) but I’ll try to see if I can make a comparison in the near future. I also park my truck in the garage so that likely affects the gas mileage in extreme temps.
Here’s some pics of my trip.
