Wednesday, July 09, 2008

MPG in my RAV4

This past weekend, we took a trip to Idaho. It was about 250 miles in each direction and for the whole trip, I was able to average right about 23 miles per gallon while doing 80 MPH on the freeway. We were late leaving, so I may have even been pressing the speed limit a little further at times on the way up there. We had 5 people (4 adults and a 14 year-old in the 3rd row seat) and a bit of gear. I had fully inflated the tires to their maximum pressure (not the pressure listed on the car's sticker) of 44 PSI. I left my roof rack on top because it supports my ham radio antenna. I did not use any fuel saving methods (like pulse & glide or drafting a truck) or anything other than the tire pressure. Since this is our first really long trip in the RAV4, I wanted to get a baseline for the future. The 23 MPG number isn't that great (the EPA estimates on this vehicle are 19 city & 26 highway), but it's not bad considering the speed and load.

I do have some history with a trip we used to make quite often. It is a 30 mile drive with about 5 on city streets and the rest a single stretch of 65 MPH 4 lane freeway where people usually drive about 75 MPH. We mostly made the drive with just my wife and I in the car. I would usually get about 25 MPG on the way up, and 22 MPG on the way back (uphill vs. downhill + prevailing winds make the difference).

The other day, after filling the tires full and using some pulse & glide, some 3-car-length drafting for 10 miles of the trip, and keeping the speed down to around 70 MPH, I was able to get 34.4 MPG on the way up. Keeping the speed to 70, but without any other methods gave me 25 MPG on the trip home that day. I'd like to play more with Pulse and Glide, but it requires that I pay a lot more attention to driving (I guess that's good) and not to my wife (that's definately bad :(

Anyway, I thought it was interesting that there is such a difference in fuel economy just by changing a couple small things (additional tire pressure, and a 5 MPH speed reduction) gave me 13% improvement.

I'm glad I have my ScanGauge to use because I'm hardly ever able to tell by looking at the whole tank of gas what I kind of economy I got for a particular style of driving. There are many times when someone will sit in a parking lot with the engine running to keep the air conditioner running. While I still check the overall mileage, it's always disappointing that it is so much lower than what we get on these 30+ mile trips that I like to test with.

1 comment:

  1. Hello from kc7-uym. Just passing through your blog for a moment.

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