dcdyd

Recently our familiay had a 5K miles trip among several National Parks in continent US. 08 RX is very comfortable for that despite that it had many marks in the front bumper after the trip .

One interesting thing I experienced is the variation in the mileage for fuel I used in different states. The worst one is from a station in Fargo, ND. The fuel is marked as 91 with 10% ethanol. RX shows about 21.5 mpg during a highway drive at the speed of 75mph. While for a full tank I added in a station inside Yellow Stone National Park, The fuel is marked as 91 and there is probably no ethanol mixed. RX shows 28 mpg at the speed of 75mph. IN most cases, the mileage shows 25-26 mpg no matter there is ethanol moxed or not.

So I wonder what grade of fuel is it I got from Fargo, ND. And why it resulted so low mileage. Could it be that there are more than 10% ethanol mixed?

Does anyone have the same experience?

mandyfig

Too many variables to make a conclusion. Good observation but can not correlate to make a judgement on root cause of the various MPG results.

dcdyd

21 and 28 is huge difference. I am not an expert on this but as a consumer I feel there shold be some difference in the fuel that resulted this. The car is at the same pyhsical condition and it is hard to believe that it is the car that caused this.

RX330inFL

I think all pump gas these days has around 10% ethanol as an additive with the exception of marine fuel and possibly aviation fuel.

Are you calculating MPG using the onboard computer or miles traveled divided by fuel used?

koric

iTrader: (1)

There are so many variables in this situation such as topography, sea level, weather, etc. I don't think its the fuel mixture. There shouldn't be that great of variance between different gas or octane for that matter.

RX330inFL

... if you got the tank actually full on the previous fill up...

Like you said, so many variables.

dcdyd

Onboard computer.

dcdyd

This is the reason I am concerned about the qality of the fuel from the statio n at Fargo, ND. It could be 20% ethanol mixed or it could actually be 87 fuel marked as 91?

jfelbab

FWIW, I live close to a station that still is allowed to sell real gasoline and I consistently and repeatably see 1.5 - 2 MPG more when using real gas vs. using ethanol laced gas.

This might be useful in seeking out those stations that are still selling pure gasoline (no-ethanol additives): http://pure-gas.org/

Using the on-board computer is often quite inaccurate. The best way to measure fuel mileage is to fill the tank and divide the miles traveled by the fuel used.

dcdyd

This is very helpful. THank you!

RX330inFL

Thanks for posting a reminder for the Pure Gas web site. In my area, I am familiar with those listed. A few less than in the past. Nothing newly added. Most are located at the marinas or on the roads nearby as I have mentioned in previous threads. There is one gem on the list for my area which also sells 100 octane ethanol free for use at the track. My Chevelle just loves it. Comes at a pretty penny though and I am afraid it won't be available much longer the way things are going.