Murano fuel economy is affected by octane rating

I also keep a log of all the gas used on my vehicles but have not run the experiment you descibes. How many tanks of gas was the experiement conducted on, and was it using the same brand of gasoline?

Based on your figures, it would take a price differential of more than $0.50 per gallon to justify the lower cost of the regular (I assume 87 octane) gasoline.

For example, for 100 miles driven using regular (87 Octane), you get 18.2 MPG and therefore use 5.49 gallons of gas. At $3.29 per gallon it costs $15.37 to travel 100 miles. For 100 miles driven on mid grade ( 89 Octane) it gets 21.4 MPG, and therefore uses 4.67 gallons. At 3.09 per gallon the cost is $16.98 to travel 100 miles.

I used those examples because in our area the cost difference between the two grades is often about 20 cents.

I'd sure like to know how many tanks were purchased to come up with those figures because if that is the only difference then the mid grade may be a better choice also because it may reduce the possibility of pre-ignition and that grade of gasoline may have better detergents. etc.

If the figures are right I would be interested to know what the mileage would be if using a premium grade, like 91 Octane.

Mark

Your math is seriously flawed, Nimrod. You have 87 octane priced at 20 cents a gallon more than midgrade.

I come up with $18.00 to go 100 miles at $3.29 a gallon

$14.43 to go 100 miles at $3.09 a gallon.

Real world calculations (assuming you understand the real world) would be

$16.96 per hundred for regular, $15.36 per hundred for midgrade.

You may now place your head back inside your anus.

Bluto©

I ran just two tanks (19 gal ea.) of the standard grade gas to reach those figures. I use mid-grade the rest of the time.

Move to Europe. Regular is 95% Octane. Premium is 98% Octane.

That would not be a reason to move to Europe.

Today I was wrong and corrected my error.

Tommorow you will still be boorish.

Mark

I've had similar results with my '06 Frontier 4.0L V-6. I don't have the mileage log in front of me, but as I recall I averaged around 1.4 mpg better on Premium than on Regular (8% or so). For the first year I owned the truck I used nothing but regular. However, Nissan clearly states that although regular is OK, for maximum performance and fuel economy, premium should be used. When gas passed $3 a gallon I decided to try premium. I used premium for 2 months (6000 miles or so) and the fuel economy was consistently better. However, it was not enough better to justify the added cost of premium. I recently switched back to regular and plan to verify that the mileage drops back to the previous level. After that, I think I will try the plus grade. If, as was the case for you, it provides a 12% increase, then I could justify using the plus grade all the time.

I have tried switching to premium with other vehicles I have owned including two Ford Expeditions. These vehicles had knock sensors and it was claimed that the power and performance would improve if premium gas was used. I never could detect any difference in gas mileage for the Expeditions when running premium.

Ed

I for one would really like to see a post with the difference in mileage given. With say a five tank average both ways it should be enough to determine which way to go. With the 21.4 and18.2 figures given by R J Talley the calculations work out that when there is a $0.50 / gallon differential then it is more economical to use the higher octane gasoline.

I just bought a new 2006 Pathfinder from the dealer. I put in three fillups of Shell 87 Octane and 1 fillup of BP 87 Octane. The car has only 1050 miles on it. The dealer gave me a filled up tank when I bought it 5 weeks ago. The results in MPG are: 16.5, 16.9, 17.4 and 16.3. I will probably run 87 Octane for a few more tanks and then try the 89 Octane if looks like this will make a difference in mileage. I am satisfied with the mileage but since I plan to keep it for a while I want to figure out the best economics, etc.

Mark