According to the owner's manual for my 2015 Q70L, I am supposed to use premium unleaded octane 96. How many folks only use the recommended octane? Anyone used a lower octane and had trouble?

1. gasoline-t601007.html
2. e15-fuel-ok-t620536.html

Why buy a performance / luxury car and complain about the cost of premium gas?
.70 cent a gallon additional x 18 gallons is 12 bucks a tank.

Owners manual says premium required.

Who complained about the cost of premium gas? I only wanted to survey owners about which octane they are using and whether a lower octane causes car trouble. Where in there is a complaint?

For those who have tried a lower octane, please don't hesitate to answer. M37xnit is trying to "gas shame" you. Please ignore and let us know the results of using a lower octane. Thanks!

The first link I intended to post (I fixed it because at first it went nowhere) has some experience from member Altered.

I have never attempted to use lower octane myself, but back when the V6 used the 3.5 engine, the owners manual forbade use of anything other than 91 for the V8 (unless in an emergency where you don't fill the tank) but allowed use of 87 for the V6 but warned of reduced performance.
When it comes to the 3.7 and 5.6 engines, the manual doesn't discriminate on the engines. It says use only 91, but 87 can be used in a pinch (again, don't fill the tank with it).

FWIW, I had a guy comment on one of my YouTube videos regarding an 06 M45. His wife had done as recommended during the floods in Texas and only put half a tank of regular gas since premium couldn't be found. They topped up with premium ASAP, but their catalytic converters were both damaged. Strong correlation as that was the only significant event leading up to the sudden failure.

I would also like to see other members' experiences. I suppose it also depends on your engine. If you had a V8, I'd be less interested in doing the experiment. Those catalytic converters aren't all that accessible.

FWIW I have been running Sunoco 89 octane E-10 in my "new-to-me" (w/ 102500 miles on it)) 2012 M37 for a bit over 2000 miles with no problems or performance issues. However I have found over the years that "summer" gasoline here in Florida tends to be a bit more ping resistant than the it's (R+M)/2 rating would indicate...

I've always used 93 (10% ethanol) Mobil or Sunoco but lately I switched to 91 non-ethanol at a local chain after being told that non-ethanol was better. But I don't know now...thinking of going back to Sunoco/Mobil.

I just found a gas station near my house that has non-ethanol. So that’s better? Please elaborate!

emanon wrote: ↑

Sat Sep 08, 2018 7:10 pm

I just found a gas station near my house that has non-ethanol. So that’s better? Please elaborate!

Leaving aside the various arguments for ethanol having no place in a gasoline engines's fuel, many of which are valid, and considering only octane it doesn't matter--91 octane (R+M/2) gasoline is 91 octane gasoline. Ethanol itself is 98.5 octane (R+M/2) I.e. it increases the octane rating of any lesser octane fuel it is blended with.

Also, read the signs at the pump--here in Florida they say "may contain up 10% ethanol"--those of us old enough to know what "real" gasoline smells like can tell how close to 10% it is by the smell. The Sunoco 89 octane I have been using smells like gasoline...

Hi welcome to the forum

I would recommend running them both and seeing if you can tell a difference. I live in Ut and I can only get 91 as the highest octane and that's what I use and I am at about 4000ft. Try them both and make your own decision

best
Andy

I run premium only.

I run premium as well i don't understand why the guys who wrote the manual would get this wrong , instruction seam simple.

Premium only. The damage that could be done to your engine isn’t worth the savings at the pump.

These engines have an 11:1 compression ratio. Anything nearing 10 needs premium fuel to prevent pinging and detonation. The engine can retard timing to help prevent pinging, but only after detonation has occurred. So basically the engine will constantly have detonation and the computers will then try to adjust.

When I bought the car (used not very long ago), the dealership filled it with regular. Car ran okay but MPG dropped to 14.
By the way, just because you can't hear pinging doesn't mean it isn't happening.

You all are opening my eyes. I am learning. Thanks for the replies and keep 'em coming.

The ethanol-free gas near my house is 87 octane. So this gas is not suitable for my car even though it's ethanol-free?

No it is not suitable. The issue is the octane rating. Not the ethanol percentage. Although higher percentages of ethanol are not good.

Non-ethanol 87 octane is good for your lawn mower, chainsaw; and outboard motors and generators if you have them...

cliffyk wrote: ↑

Sun Sep 09, 2018 6:36 pm

Non-ethanol 87 octane is good for your lawn mower, chainsaw; and outboard motors and generators if you have them...

Dam I almost put this in my car.

Oh no, this is getting confusing really quick.


OP,
Generally, non-ethanol fuel is preferred for non flex-fuel engines (to my knowledge, that's all of Nissan engines sold in the US, except some Nissan Titan variants).
Then, the engine designer sets the fuel recommendation aka the octane rating.
For example, a 2018 Nissan Versa comes with a fuel recommendation of no lower than 87 AKI. If I owned a Versa, I would be looking for non-ethanol 87 octane fuel.

However, due to government regulations & incentives, it is difficult to get non-ethanol fuel in many areas of the US. Those gas stations are available, but might not be easily accessible.
Ethanol in itself isn't all bad or all good for fuel (points arguable from both sides). Again, think of GM flex-fuel cars that use up to 85% ethanol

So yes, you can use whatever octane fuel with whatever amount of ethanol in it... As long as the manufacturer OKs it. Refer to satown's post above.

I gave you objective answers to your questions earlier, but I'm curious. What is the goal of the exercise - just to know or is it to try and use the cheapest fuel allowable? (I do use the cheapest fuel allowable for my car, so there's no shame in that goal).

I think referring to your owners manual would be the best course of action to ensure longevity of your car.
Straying from that will put you in the land of subjectivity, where it is hard to measure whether your summer/winter gas in South Dakota is the same as that someone else buys in New Mexico.
And hard to measure whether it is pinging a little or a lot from your driver's seat.

I live a simple life and at the gas station it's an easy decision -

• V6. avoid anything over 15% ethanol, and anything under 91 octane
• V8. avoid anything over 10% ethanol, and anything under 91 octane- because the people that made my car said so. I don't find that to be subjective.

But of course, this is my opinion so what I think is set in stone might be viewed by someone else as open to interpretation.

I started this post because my owners manual says "use unleaded premium gasoline with an octane rating of least 91AKI (Anti-Knock Index) number (Research octane number 96)". Not fully knowledgable what this meant, I thought it meant I had to find gas labeled as Octane 96. Since I had never seen such a thing, I assumed that everyone was using some other rating and Infiniti was just requiring the highest rating possible, fearing recommending a lower rating could haunt them. I know now I was totally off-base. In my defense this is the first car I have ever purchased that didn't allow regular unleaded.

So, I only wanted to see what others were using and what happened when someone used gas with an octane rating below what the manual requires.

Gotcha. It makes sense to me. I like to learn as well.


From a prior posting of mine, here is a blurb:

... premium with an octane rating of 91 AKI (also called the [R+M]/2 method, which is what you'll see at most pumps at US gas stations)...

Basically the number you see at the pump is the AKI number and is in line with the manual.



Back to that Versa example, the owners should use 87 at the pump since that is the AKI number the manual calls for.

They shouldn't use any lower octane fuel (not that you can find it readily in the Midwest. Although I vaguely recall seeing 86 somewhere out in the sticks)
Neither should they use premium with the hope of better performance... Unless the manual says so. (Refer to maxima example below)


Going off satown's angle and staying within Nissan: my 97 Maxima was perfectly fine running 87 octane, but promised better performance with 91. The fuel door said "premium recommended", my V8 Infinitis have said "premium only"

This Maxima engine had a compression ratio of 10.0:1. The interwebs say the versa engine could vary from 9.5:1 up to 11.2:1. I could not readily find the correct info for the 2018 versa in my example.

As you can see, it's not cut and dry and even within a car manufacturer, we can't laterally assume anything. I applaud you for reading the manual. After all, it is the first reference point upon which we can discuss further.

I tried my best to keep this brief, but wanted to offer as much factual data as I could.
I am also eager to see whatever others are experiencing with different octanes though.

Thanks for all the information! Now it's clear to me. Where I live the only gas that will meet the requirements in the manual is premium unleaded 93 octane. Now I know that if I run across 91 octane, it is acceptable. I also have learned that the ethanol-free gas at a nearby station is no good for my car because it's only 87 octane. It's great that it is ethanol-free but the octane level is not sufficient.

Speaking of ethanol, I have also learned from this post and from reading my manual that I must know the percentage of ethanol in the gas. For my car that percentage must be no more than 10%. That's something I have never paid attention to until now. Yesterday when I purchased gas, I saw the ethanol level clearly posted. It's amazing that until now I've never noticed the labeling at the station.

Finally, the only decision left is which brand. It's clear to me that I must stick with Top Tier. Someone I know who has driven Infiniti cars for many years recommended I use Shell, Mobil, Exxon. and Texaco only. So far I am using Shell because it's close-by.

Here's a good read, with more about octane than you likely want to know--note the distinction between pre-ignition ("pinging") and detonation ("knocking")...

emanon wrote: ↑

Mon Sep 10, 2018 3:50 am

Thanks for all the information! Now it's clear to me. Where I live the only gas that will meet the requirements in the manual is premium unleaded 93 octane. Now I know that if I run across 91 octane, it is acceptable. I also have learned that the ethanol-free gas at a nearby station is no good for my car because it's only 87 octane. It's great that it is ethanol-free but the octane level is not sufficient.

Speaking of ethanol, I have also learned from this post and from reading my manual that I must know the percentage of ethanol in the gas. For my car that percentage must be no more than 10%. That's something I have never paid attention to until now. Yesterday when I purchased gas, I saw the ethanol level clearly posted. It's amazing that until now I've never noticed the labeling at the station.

Finally, the only decision left is which brand. It's clear to me that I must stick with Top Tier. Someone I know who has driven Infiniti cars for many years recommended I use Shell, Mobil, Exxon. and Texaco only. So far I am using Shell because it's close-by.

Pretty much sums it up, just a little more clarification though, at least IMHO. Owner's manual lists using the premium 91 octane first and foremost. I interpret this as ethanol free, as later wording in the manual says that Infiniti/Nissan supports efforts towards cleaner air, i.e., the use of reformulated gas as a second choice (my interpretation), no more than 10% ethanol. With that said, I use ethanol free 93 premium, here in NC. We have several stations that carry e-free gas. Quality Mart is the one I usually use, but Murphy's carries it, as well as Chevron and a few independent stations around town. You'll get better mileage, offset by the higher cost per gallon as far as saving money.

I have been searching for ethanol free that is at least 91 octane and can't find it. I found a website that lists ethanol free stations and every station within a reasonable distance from me is 87 octane.

emanon wrote: ↑

Thu Sep 13, 2018 6:42 am

I have been searching for ethanol free that is at least 91 octane and can't find it. I found a website that lists ethanol free stations and every station within a reasonable distance from me is 87 octane.

I understand - 91 or 93 premium oxygenated will be fine. Not worth driving out of the way to use the e-free stuff. It's convenient for me, otherwise I would use what's available.