The Nissan Path

My 2013 5.0 V8 Mustang GT will make less power running 87 octane then running 91 or 93. This is well documented and running the stock tune which I am not so I have to run 93 in mine. Will the R51 4.0 V6 make less power running 87 other then 91 octane? I feel no difference between the fuel grades. I do wonder though every time I open my fuel door there is a sticker that reads "Premimum fuel recommended for maximum performance"

On a side note I run 87 in my Pathy except when I tow my camper this summer I will only run 91. I don't want to take the chance of spark knock when towing 5,000 lbs.

The knock sensor will prevent spark knock, by retarding the timing accordingly, and theoretically producing less power.

I've only noticed this when the engine is under extreme load, like when pulling my camper.

A bigger reason to run 91 in my area is to avoid ethanol, no ethanol in this grade of fuel...

Ethanol is in ALL grades of gasoline. At the very least 10% of it is ethanol. There are no more stations selling 100% conventional gasoline.

Not where I live.

Not where I live.

There's a difference between 87 and 91+, although it's pretty subtle unless you're into the go pedal hard and often. I have a couple very steep hills on my commute that I can just pull in 5th gear at 60mph when running premium but need a downshift with regular fuel. There are times when it's super humid that the same is true regardless of fuel type, so it's a very slight difference at lower rpms. When you open it up though you can tell more obviously. I usually pass several cars a day on my commute and there's a noticeable difference at WOT.

I usually try to run at least mid grade but it depends where i fill up. The station I prefer to use is only $0.20/gallon more for 93 octane so I'll usually fill-up with that when convenient. I'm at 135k miles now and I've noticed the last 20k miles or so it gets slightly better mpg on premium. The station on the other end of my commute charges almost $.0.60/gallon more for premium so I just fill with 87 there.

Just wondering Skinny2 at 135K on your "08" are you on the original timing chain ?

Yes, original chain. I don't have any suspect noises from the chain/guides either.

I'm at 160k miles on my original chain as well. 2005.

jeepguy07 wrote:Ethanol is in ALL grades of gasoline. At the very least 10% of it is ethanol. There are no more stations selling 100% conventional gasoline.

You can get ethanol free gasoline in many places in North America:

http://pure-gas.org/

In my neck of the woods, people run the ethanol free blend in their 2-stroke engines, especially if they are a little older and designed before ethanol was as prolific as it is now. Ethanol is really hard on rubber seals designed before ethanol was in use.

Personally, I buy the cheapest gas I can find, which means I do run ethanol in all of my vehicles, lawn tractor, snowmobile, etc etc. But as the website above demonstrates, companies definitely are making ethanol free gas.

I notice a decently significant difference in fuel mpg and how long a tank lasts as far as miles go when I use higher octane fuel. I know this because my driving habit doesn't change and I do some pretty consistent driving to and from work @ about 80mph daily for 17 miles one way and about 40 mph for 4.5 miles in the same shot. Higher octane last me about 315 miles per tank lower octane I won't break 300. Roughly 285 miles per tank. Is it worth the 4 extra bucks at fill? Thought the year id say yes.


This is with 91 oct with 89 I'll get 47 at the very best @ this mph and rpm
Please excuse the SES . That damn evap leak. Po456 [/img]

I hauled gas for 8 years all over Ohio, Pennsylvania, and West Virginia. I quit in 2011. As of then you could not load conventional gasoline ANYWHERE. Even branded product had 10% ethanol in it. It is now mandated in the U.S. that ALL gasoline have at least 10% ethanol in it. I don't necessarily agree with it, but it is what it is.

08PathPounder wrote:I notice a decently significant difference in fuel mpg and how long a tank lasts as far as miles go when I use higher octane fuel. I know this because my driving habit doesn't change and I do some pretty consistent driving to and from work @ about 80mph daily for 17 miles one way and about 40 mph for 4.5 miles in the same shot. Higher octane last me about 315 miles per tank lower octane I won't break 300. Roughly 285 miles per tank. Is it worth the 4 extra bucks at fill? Thought the year id say yes.

Going to have to try this experiment. Most of my driving is city 13-15/mpg therefore I'm filling up around the magic 285 mile number you mentioned.

I've started consistently running premium over the last month or two and my mpg is up 1mpg or better. Pretty much pays for the fuel premium.

This is the best "Distance to Empty" I've gotten using regular 87 octane gas. This was during a 1,600 mile road trip to Canada.




Disregard that 28.4mpg. With all highway driving, I only average 21-22mpg. With mix city/highway I average 16-17mpg.

I only use 87 octane so far.