Johnhav430

I just use premium, as the car was designed for it. Oh, I did cheat 2X--the tank is huge. I had a full tank of 93. When it went down, I put about 8 gal of 87 in, with the understanding that in CA there is usually only 91, no 93. So my blending still met 91, or almost, maybe 90.8x.....

I will say that I operated my Maxima for 18.5 years on regular, and it was designed for premium.

We used to be able to say that all cars can operate on regular, but that may no longer be true. My 335i says minimum octane is 89. In the world of turbocharging, this seems to have come about, i.e. even the knock sensor can not compensate for < 89.

A nice example where super unleaded is pure marketing....the 2015 v. 2016 VW GTI. The fuel doors of the 2015's say premium unleaded. The 2016's say regular 87. The cars are identical. In the brochure and manual of the 2016's it will say that you will not achieve the HP rating shown unless premium is used.

I think it's important to understand what the octane AKI values actually mean. Basically, predetonation, nothing else. some say it measures smoothness, power, mpgs, detergency, etc., but not really. The worst case is when a car was designed for 87, and a person fills it for 93, because he loves his car and wants it to have the best.

edit I did cheat twice, but maybe I should do so more often, then again it saves only about $2.xx

JefDav84

I will say I did put regular 87 Octane in my LS 430 to save a few bucks once. Come to find out I noticed when I would hit the gas while entering the highway I would get a god awful smell come through the vents (Like rotten egg smell). Once I let tank run all the way out I have only put premium in since, and I have not had one single issue with any smells when I punch the gas pedal down.

Johnhav430

Interesting I was the 2nd to last to reply to this thread, and I did it again. While I was on business, there was no familiar $2.399 93 premium, so on a full tank of 93, I added 6 gal of 87 @ $2.319, and according to my calculations, I woulda dropped the octane to about 91. My reasoning is most of Calif. only has 91, so 91 is sufficient. Then, on my way home, I was down 19 gal, and filled at Costco 93.

I ran my Maxima for 19 years on regular, when the fuel door says premium. Nothing happened, except the car did not achieve the 190 HP/ 205 ft. lbs. as stated in the brochure. But the LS I always use warehouse club premium. Who knows if the 2 prev owners did or not.

Again, the only thing that will happen when using 87 is less output--the car should be able to adjust the timing. I could be wrong since I bought this car used--there are cars that "require" premium, and those that "recommend" premium. Never put regular in a car that "requires" premium. On my 335i, the manual states that 89, not 87, is the minimum octane. I shudder to think of all the times people with loaners or leased cars filled with 87.....on my wife's car, the manual states 87 is sufficient (using 93 is burning $$$$ out the tailpipe)

caverman

I'm on my second LS430 and have run regular gas in both. I never smelled anything different nor had any performance issue.

When I got my first LS430 I used to run premium but then started running regular and my performance seemed the same as well as the gas mileage didn't decrease. That being said, I don't hot rod around in this car. I usually just grampa the car around town with only needing to occasionally get on the car a little hard to get around someone or get on the highway etc. I average 19 - 20 mpg with mostly city and a little highway driving.

However, every 15k miles or so I run a bottle of fuel injector cleaner like Seafoam just to help keep the injectors clean.

Johnhav430

I'd like to respectfully point out, there's no correlation between octane, and mpgs. It's not what octane measures....I ran the Maxima for 19 years on regular, when the fuel door says premium is recommended, and regular can be used when not available. When the car was new, it routinely topped 30-32 mpg on the highway, when the EPA sticker was 27. It just never produced the 190 HP / 205 ft. lbs. as a result of my using regular.

rjm

I've had the same experience. I'm on my 3rd Lexus and have always run regular gas in all of them. When I bought my new LS430 years ago the dealer recommend regular gas. He said the pump at his dealership had only regular in it and that's all they ever used in their loaners, etc. No decrease in performance noted and no mechanical problems with any of them. And everything smells fine.

nedear1688

Further research on the web for better understanding what should I fill up my LS...I checked the fuel door again and it said "Premium Unleaded Fuel ONLY", if it said Recommended than I would not hesitate to fill up regular 87 octane in it. So...my way to save $$$ is going to Costco wait inline to fill up premium for less!!! At least Costco fuel now listed as Top-Tier.

Johnhav430

Costco is the way to do it, sometimes premium is only 17 cents more than regular. At any old place, I have seen 80 cents more for premium, which I would never pay....and with a 22 gal tank, so far, I have been able to wait until I get to a warehouse club. Went 403 miles the other week before filling up again.

nedear1688

Yup, it's always $0.20 over the regular here in California! My tankful can go over 450 miles before the low fuel message came on, but I routinely fill up the tank like 380-395 miles and I pumped 18+ gallons. I only use my LS weekend and Friday, my daily commuter is a 2011 Prius which I also use Costco gasoline.

Owning my 1st LS almost like a milestone for me!!! Finding a mint condition one almost impossible but I manage to find 1 over the pass 2.5 years, most of them sold before I even go test drive it.

jimisbell

Consumer reports says that Premium is no better than Regular. PERIOD. They have NO reservations.

All lower octane does is make the fuel morel prone to pre ignition (PING) And modern cars have a computer to suppress PING so you dont need the higher octane.

Even the Federal Aviation Agency allows many planes to convert to Auto Gas which is FAR below the (min)100 octane that is available at the air strip.

I use regular in all my cars (except the Formula Alantic race car). Never an issue. My Formula racer uses 130 octane because that is ALL that is available at the track and you MUST use it. Its a monopoly to make money for the track at $6 a gallon.

2KHarrier

That was pretty good.... I see what you did there! "FAR below the (min) 100 octane" - FAR = Federal Air Regulation.

Very clever, Jim!

Johnhav430

Not period. One of my 3 cars, in the owner's manual, states, 89 is the MINIMUM and 91 or higher is recommended. This is just one of those topics where it will never end, and there will be many differing opinions.

Again, I ran my Nissan for 19 years on regular, when the fuel door says premium, regular can be used when not available. This does not apply to all vehicles.

On the LS430 I'm going to keep filling with premium, period. On the Nissan? Regular.

Not sure what the context is with CR, they're biased anyway, but premium is better when it comes to predetonation. It's not better for taste, color, quality, hardness, goodness, etc.

Gronemus

Good catch 2K. I thought that he was only referring to his Formula Atlantic Race car...

warminwisc

Just got back from the Sierra Nevada premium is 20 cents difference to regular. Here is Wisco it is up to 70 cents difference. Any ideas on my the difference?

2KHarrier

First guess would be good ole' Merican Capitalism at it's best... It used to be a standard 10 cents difference between each grade.