For the couple of years I've had the coupe I have filled it with 93.

With gas prices the way they are I was tempted to experiment. Added about 40% of 87 to 60% of 93.

I've done it twice with a full tank of 93 in between.

First time, seemed strange, I actually got somewhat better gas millage (based on my navigation system's info). Second time somewhat worse. I usually average around 17.5 MPG.

Otherwise driving seemed not to be effected. No pings that I can hear. In this hot weather driving with AC full blast.

Anyone else attempt to mix grades? Any downside?

 

i have heard that mixing gas can hurt the car. but that was just hear say, i am not exactly sure that is right.

 

mixed it to 95-98 octane once.. felt the same.. waste of money lol.. but i was bored..

btw theres a bunch of formulas on the 350z boards if u wana go look it up there

 

Your mix of 87 & 93 octanes should be fine. The end result would be about 91 which should get you optimum performance.

Even if performance is off and gas is sub-standard, I doubt you'll hear any pinging. The computer will retard the timing to prevent that.
Your performance will be noticably affected tho.
I wouldn't go any less than 91 octane.
C.

 

That is excatly how gas stations get the so-called 'plus' grade of gas, between standard and premium, they mix the standard and premium (I think it's done within the pump itself). No refineries create 'plus'. Here in NM, standard is usually 87 octane and premium is usually 91, so the plus is 89. I think it's just a scam to get folks to spend a bit more. I don't see how you could harm your car by mixing to produce a 91 octane blend.

 

If you do a 60/40 split with 93 and 87, respectively, you will get 90 octane

It's basic chemistry. You are mixing two diiferent types at different percentages. But if you're doing it to save money, you really aren't saving much. 40 percent of a 20 gallon tank is 8 gallons. Usually 87 to 93 is 20 cents different. So that's 1.60 you save. It's your call, save a 1.60 and pump 90 octane, or pay the extra 1.60 and get 93. If you can afford a 40k dollar car, you should be able to afford an extra 1.60 every time you fill up.

Just my 2 cents

Hooman

 

It's funny because in every gas thread that someone mentions about using cheaper gas or finding an alternative someone is quick to say its only an extra dollar or two. Which you are right, but you fail to take into consideration that gas has gone up well over .60 in the past six months or so, atleast where I live. So then if you look at that increase it's quite a bit more then 1.60 extra per fill up.
Lips

 

Right but you have to pay the bare minimum anyway, unless you don't drive your car. If you want to put in the cheapest (87 octane) you have to pay 2.50 a gallon. This is the cheapest gas you can run your car on. Since you have to pump gas and drive, for 1.60 more you can get better gas. In San Diego, prices are near 3.00 a gallon (for 87) and have been in the high 2 dollars for a while now...we're use to it by now.

Hooman

 

In CA our highest gas is 91 , so if you mix 87 & 93 in the proper ratio to get 91, the car should be OK.

If you are at a gas pump that has octane selection buttons & a single pump, I would think you should put the 93 in first so that when you pump the 91 you get what's left of the 93 in the hose.

 

Gsedanman, especially on hot days (or when the engine is heatsoaked) I get some slight gargle (knock/ping) for a maximum of 2 seconds upon accelerating from a stop and then it goes away (I'm assuming the sensor has kicked in). Problem is that it happens all of the time when the motor is hot and is under the slightest load.

I run 91 octane and can't get rid of this. Have you experienced this?