MPGs and Fuel Brands can be Compared - GreenHybrid

HyCAMBill · #1 (**permalink**) 03-31-2008, 08:44 PM

About a month ago I visited the discussion category of Fuel Economy and Emissions appealing to all hybrid owners. I was truly impressed with Bob Wilson’s post about how different gas stations or brands can affect your gas mileage. Here is the original link...

http://www.greenhybrid.com/discuss/f...gher-mpg-1266/

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Bob has a super cool chart with several gasoline brands that were tested in his Prius. He drove his car up a steep grade and was able to measure the gasoline’s Watts/Gram generated under a load. On Bob suggestion I did my own test. My results were posted among all the other hybrid owners can view it but I would like to post this information back over here with the other Camry information.

In my neighborhood we have a wide variety of stations to choose from. Last summer I checked the temperature at all at these stations and found Phillip 66 to be the most consistent @ 60 degrees. I was surprised how hot the gas was at the other stations.

Over this past winter my mileage had dropped to 33 – 34 mpg for what I thought was the cooler weather.

At Bob’s suggestion, I followed these steps: I live near a long STEEP grade on I-70 called Mont Vernon Canyon. My test was from Mile post 260 to 255 near the top, a 5 mile testing hill. I set the curse control at 60 and turned the heating and cooling off.

I did not run the car out of gas between tanks but emptied the tank to the “Cursing Range” read about 10 miles to go and then added 10 gallons. At least 90% of the gas was from the station listed below. I used only the 85 octane, (Colorado’s 87 octane). I have not tested the mid-grade or higher yet.

I made three trips up and down the grade, a total of 16 miles round trip on each brand of gas. The mileage would drop for each trip and then level off. I believe this was the extra battery power level being used up in the first trips. I believe the last trip value to be the most accurate reading.
Overall the MPGs variances were not significant but I notice a large increase in the overall tank averages.

Safeway was the clear winner. What was most interesting was that the overall tank average moved up from Phillip 66 - 34 mpg to Safeway’s--41 mpg. Sinclair’s overall tank average was 39 mpg.

I understand Safeway receives most of its gas from a refinery in Wyoming. Most of the gasoline in Colorado comes from one refinery located in Denver. The downside of Safeway is that they will buy from the local refinery from time to time.

Here are the results:
Safeway Outside Temp 36 degrees
Trip Number 1—18.9
Trip Number 2—18.9
Trip Number 3—18.8

Sinclair Outside Temp 37 degrees
Trip Number 1—18.4
Trip Number 2—18.2
Trip Number 3—18.2

Bradley Outside Temp 41 degrees
Trip Number 1—18.3
Trip Number 2—18.3
Trip Number 3—18.2

Shell Outside Temp 41 degrees

Trip Number 1—18.1
Trip Number 2—18.0
Trip Number 3—18.0

Phillip 66 Outside Temp 43 degrees
Trip Number 1—18.1
Trip Number 2—17.9
Trip Number 3—17.7
Trip Number 4—17.7

Much is made about pumping gas slowly, buying gas in the morning to get colder gas. It appears the power produced by the gasoline will have a greater impact on improving the value received from your purchase. This will become a greater issue as the price of gas climbs later this summer. Nothing like knowing the REAL value for the prices paid.

My final thought would be the computers in the TCH have the ability to measure performance of gasoline over time considering all the data points that are available within the computers. The car’s computer could set benchmarks for the best performing tanks of gas and measure against the current tank. Engineers could design a Power Scale from poor to average to excellent. Hybrid cars are sensitive to minor changes that can make a big difference. Know the true quality of the gas could help making better decisions about what brands and locations to make your purchase. I'm sure these values will change over the coming summer months. Each station's delivery could be different, tank to tank.

I thought you would like to know this and you may want to consider this kind of test on your daily commute.

Cheers!

Bill

mikecism · #2 (**permalink**) 03-31-2008, 09:48 PM

This does not suprised me. Even in my old 80's 4 cylinders, high octane would get me more mpg than lower (regular) octane. Easily 5 more mpg, sometime up to 10 mpg, esp. on highway.

However, with fuel injection and modern engines, I don't know if this is still the case. I know Honda's (non-hybrids) show nearly no difference between using low and high octane gas.

I'm game to try this out and see...have a full tank of 87 now...will do the next with 91 and see. (same brand).

HyCAMBill · #3 (**permalink**) 04-02-2008, 06:47 PM

I am try some 91 now for the first time. This should be interesting compared to the others that were tested. So far it's a bit better, I am not sure it will pay for the over all increase.

I look forward to seeing your results!

Bill

chris_h · #4 (**permalink**) 04-04-2008, 11:55 AM

Are the units of temperature degrees celcius? Are the numbers given for each trip in mpg?

HyCAMBill · #5 (**permalink**) 04-04-2008, 12:09 PM

The temp is in Fahrenheit and the trip was measured in mpg uphill.

I also have the information using premium 91 octane. The results were surprisingly low! It appears the motor was designed for the lower Octane fuel.

Safeway Premium Outside Temp 54 degrees
Trip Number 1—18.1
Trip Number 2—17.9
Trip Number 3—17.9

Bill

coolshock1 · #6 (**permalink**) 04-04-2008, 12:46 PM

If you were to switch to 91 Octane and gained 5mpg would it really be worth it? I figure it would save a couple hundred over a year, but you would be putting up roughly $.20 per gallon more upfront to achieve that savings. 5mpg @17.2g= 86 miles. With say it bumped you from 34 to 40mpg that would be 2.15 gallons of gas. But you would pay $.20 more per gallon on 17.2 gallons appr. = $3.44 which thus reduces the saving to 1.15 or a $3.956 savings appr. If your like me and fill up 1 time a week for lets say 50 weeks (allowing for vacation) Thats's approx $197.80 a year savings. Now if your not in it just for the money then you would save approx. 107.5 gallons of fuel. Now if you drive less than me (20800 miles\yr just for work) Then the savings would be even less.

HyCAMBill · #7 (**permalink**) 04-04-2008, 01:04 PM

I totally agree. It is not worth the money at all! I made one extra trip just to be sure and I had the same reading of 17.9. I notice the engine runs a bit smoother.

If you take your logic and switch from Phillip 66 to Safeway 85 octane, the savings would be $241/year. Given 15Kmiles/year, 3.20/gallon.

The down side is spent 240 dollars buying the last tank of premium gas!

Bill

mikecism · #8 (**permalink**) 04-04-2008, 01:55 PM

Quote:

Originally Posted by HyCAMBill

The temp is in Fahrenheit and the trip was measured in mpg uphill.

I also have the information using premium 91 octane. The results were surprisingly low! It appears the motor was designed for the lower Octane fuel.

Safeway Premium Outside Temp 54 degrees
Trip Number 1—18.1
Trip Number 2—17.9
Trip Number 3—17.9

Bill

Interesting...is that mpg?

I had a similar experience on a non-hybrid car - high octane had no effect FE. But I have had others where it did