RV Fuel Economy


I really like tracking data and doing statistics. I’m a nerd an engineer. So on our trip, every time we filled up the gas tank, we recorded our odometer reading and how many gallons we put in. Some Excel slicing and dicing and we get some cool insights.

First off if you’re just joining us, we drive a 1989 Winnebago Minnie Winnie Class C motorhome. It’s 26 feet long and weighs about 11,000 pounds. It’s based off of the chassis of a Ford E350 van with a 7.5 liter 460 big block V8 engine that provides 230 hp. It’s a glutton. To make things worse, we tow a 2000 pound Pontiac Vibe behind it loaded down with a couple hundred pounds of kayaks and gear. So prepare yourself because the mileage numbers aren’t pretty.

In the graph, the blank space is from when we went to Canada and didn’t necessarily fill up every time because we knew gas would be cheaper just up the road or something. The catalytic converter got replaced after tank 15, notice how the average jumps after that?

Over the course of six months of summer driving towing a car behind the RV we burned just over 500 gallons of gasoline and averaged just under 7 miles per gallon overall. Eww. Sorry planet. At the same time, how many miles per gallon does your house get? We also drove the car about 6000 miles at about 30 mpg for 200 more gallons of gas.

Two bits of good news though. First, about halfway through the trip we needed to replace the catalytic converter. We knew something was wrong when we started losing power and lo and behold our stats show that just before it died, we were only getting 4.8 MPG. After we replaced it though, our average fuel economy went from 6.85MPG to 7.5 MPG. Assuming gas stays about the same price, it will take about 22,000 miles of driving to pay for itself completely.

Second, my parents are awesome and for our anniversary last year offset our carbon usage for the year. Thank you!!! Fifth anniversary is wood and carbon offsets are usually planting trees, get it? They do something super cute for our anniversary every year and keep with each of the traditional anniversary gifts (did I mention they were awesome?)


So, math and analysis hat back on for a second, 700 gallons of gas * ~20 pounds of CO2/gallon = 14,000 pounds. 10 Tonnes = ~22,500 pounds. Add in 3 tanks of propane for cooking and some natural gas for heating the apartment we’re living in for the winter and I think it worked out just about perfectly. I think we’ll plan on trying to offset our RV fuel usage every year since it will only cost us about $100. If you want to to, please check out https://carbonfund.org/individuals/ and please let us know if you have another favorite offset provider and why you like them.



10 thoughts on “RV Fuel Economy

  1. I’m new to this kind of stuff. Could you explain exactly where this $100 “donation” would go, and how exactly would it be spent to “offset” CO2 usage?


    1. I’d recommend you check out the “Projects” pages on carbonfund.org. https://carbonfund.org/renewable-energy/ is one of the three pages they have in this. Basically they do a whole assortment of things like building wind turbines or landfill gas reclamation and power plants, or Amazon rainforest reforestation. Each of those are projects decrease the amount of carbon that is in the air or will go into the air.


  2. With a similiarly sized and aged rv, I was thinking 7-9mpg would be what I’d get. I won’t be towing anything so that’ll help a bit, but then again the rv will be the grocery getter. It helps to see your numbers, thanks!


    1. You’re welcome! For us towing the car is the only way to do it because it gives us an emergency engine if something breaks and it allows me to go kayaking and carry the boats. We met a few people who used their RV as their grocery vehicle and almost every one of them was looking for a way to tow a car or a scooter or motorcycle or something. The worst was national parks. Only having an RV for national parks made it extremely difficult for people because they sometimes weren’t even allowed on the roads. If you’re spending most of your time bouncing between RV parks it shouldn’t be too much trouble, but think long and hard about what you want to do on the road.


      1. That makes sense for your needs for sure. As the only adult, I don’t think I can handle towing a vehicle. I have no towing experience and 25ft to drive is scary enough for me. Also, I don’t own a car! I borrow one from my mom and won’t be bringing it with us. So, that kind of makes the decision for me, ha. I will bring my bike with child seat and bike trailer.


  3. Wow, thanks for this. I just bought almost the same rig, except it’s called a Warrior but with the same engine. I was surprised my my numbers as well. I went looking for solutions to 6 MPG and found your entry. I was going o start with tire pressure. The door sticker says 50 psi but the rims say 65 and tires say 80 max so I was thinking of going with 65. What was yours at I wonder? What kind of oil? 40?


    1. Recommended tire PSI can be affected by how heavy of a load you’re carrying. The heavier the load the higher the PSI you’ll need to run. Going off the door stickers, it always looked too low once we had it actually loaded with 2 people, a dog, dishes, clothes, water, black and grey tanks, fuel, etc. I obviously wouldn’t exceed the rim or tire max numbers, but personally I had no aversions to going over the door sticker as we were really close to the GVWR. Watch the tire wear to make sure the tires aren’t bulging in the middle (over inflated) or wearing on the outside edges (under inflated). I don’t have this rig anymore to check what we ran unfortunately. For oil we ran the standard recommended in the manual.


      1. I appreciate your response. I’m trying to determine if my cat converter needs replacing. Makes a little rattle when the engine is warm and I think it’s plugged. What prompted you to replace the converter?


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