FYI: MPG With Various Accessory Add Ons

First off let me start that this is by no means scientific. I just wanted to pass on my observations with respect to fuel economy given different accessories I add on to my car for different modes of travel and use. I feel this would be a good to know in the event you are considering similar add ons.

I have a 2011 Prius IV's loaded with moon roofs to start off with. It averages 46 MPG on a daily basis under combined driving conditions averaging around 45-60 MPH. This MPG is achieved with a Curt 1.25 hitch receiver installed along with a Thule 917XTR T2 bike rack installed. With the bike rack removed MPG increases to around 48 MPG, and before the hitch receiver I was able to max out at 50 MPG if I really paid attention.

Adding bikes onto the bike rack continues to drive fuel economy down by about an additional 2 MPG.

Now add on the Thule Aero Roof rack system with a Thule Atlantis 1600 cargo carrier along with the bike rack set up - pretty much everything I can throw onto the car to include the cargo carrier packed, car packed, and bikes on. I have made multiple road trips well over 6K miles with this set up at an average of 70 MPH and it has a drastic effect on fuel economy. An average across an entire trip would be around 36 MPG.

In short the bike setup does not have a huge effect on fuel economy where as adding the cargo carrier does. A note of fuel - using budget fuel typically resulted in sacrificing about 2 MPG, where as better fuels with additives like Shell and Chevron led to an increase in fuel economy in similar fashion.

Hopefully this helps anyone considering similar add ons and their effect on fuel economy. As for the Thule products - love them and would reccommend.

 

I do not remove the hitch receiver. It is bolt on and would be a PITA to constantly be taking off. Thereby the hitch receiver has been on for quite a while. I just leave the actual bike rack on as well and fold it up. It gets a fair amount of use and I prefer the ease of use. Before I was getting around 48MPG with neither the reciever or rack, now about 46MPG. I guess I should have made that clear. I think the reciever weighs about 75 pounds or so and the bike rack is similar.

In any event I am well versed on how to drive the car, on #2 and 3 right now. No matter what I do I phycially cannot break about 46MPG across a full tank given the set up with a bike rack installed. Like I mentioned I could do 50 without the setup, but typically closer to 48.

The cargo carrier crushes MPG.