Nissan Kicks 89 octane

[circuitsmith]

Originally Posted by lexus114
That's why I'm trying to figure out why it runs better on the 89 octane.

I'll repeat my last post:
Hot ambient temps increase spark knock.
So on a hot summer day many cars with knock sensors can benefit from higher than the minimum octane.

In hot weather the knock sensor causes timing to retard and reduce performance.

 

[PolarisX]

Originally Posted by bbhero
Originally Posted by lexus114
Yeah I know real funny right? I do believe it benefits from at least the 89 octane. especially with the summers here in GA



Am I reading this right that the motor has a 10.4:1 compression ratio ??

If I read that correctly... Well that's interesting because the 3.5 L VQ motor in my car has a 10.3:1 compression ratio and it recommends running 93 octane.... In the manual of my car it says one can run 87 but performance and gas mileage will both be lower... I run 93 in my car.


Try a 1.4L with 10:1 with a turbo, and a transmission that with stock tuning with do anything it can to keep you at or under 2000 RPM. If you have a KR gauge it looks like a rave running 87 as the manual says you can.

 

[lexus114]

My wife had a 2015 Buick Encore with a 1.4 liter turbo. It was flat on its face on 87 octane. So I ran the mid grade in that as well. But that was a turbo. So it was understandable.

 

[homeyclaus]

If OP's empirical evidence says his Kicks gets better MPG, and it feels better to drive, who am I to argue? ECU programming is to advance timing until knock is detected, and I am sure every engine has a sweet spot that's slightly different with manufacturing variances. This might be even more true for some of the CVTs and their zillion software revisions.

I worked it out of a Maxima of mine way back when to cost per mile, and it was something like a tenth of a cent cheaper to run 92/93 in it per mile.

Conversely, I had to feed my Focus ST regular gas in the winter to have any hope of being able to keep the snow tires on it attached to the pavement. Yes at the track and cross courses, highest octane for a couple of tanks will win it, but for a DD especially in winter, de-tuning was looked into - the thing made an 80's VW GTI deem docile.

 

[kschachn]

I wonder whatever happened to that OP.

 

[Cujet]

Your brain is mapped to believe the extra money you're paying for fuel is giving you performance perks.. You'll never see noticeable gains like that especially in an engine like that and not immediately either it would take some mileage to see change but that would be in a higher output and high displacement engine.

Only thing you'll notice in slightly better mpg

Well, that’s why I always feel better about my cars when I wash and wax them.

of course, many modern engines can adequately take advantage of higher octane. The knock sensor(s) will provide real time knock information and event rates are often furiously calculated. leading to not just an instant improvement but additional gains over the long term.

 

[gathermewool]

Well, that’s why I always feel better about my cars when I wash and wax them.

of course, many modern engines can adequately take advantage of higher octane. The knock sensor(s) will provide real time knock information and event rates are often furiously calculated. leading to not just an instant improvement but additional gains over the long term.

Wash = 10 HP
Clay = 15 HP
Wax = 50 HP

At least!

A knock sensor needs to sense knock to retard timing. If the fueling/timing maps max out well below where 87 octane would knock, you will experience ZERO gain from higher octane. Also note that there are individual cells that determine timing and fueling for a given RPM and load. A higher octane might result in better WOT and/or near-redline performance, but that doesn't mean the lower load/lower RPM cells will allow for any more advancement? Why? Because you weren't knocking at low load/RPM on 87, so you won't on 89+.

I'm not one who changes his oil super frequently for peace of mind, but I can understand why some of you do. I'll never agree with you, but understand its power of persuation. I, for instance, will run higher octane, even if it only provides a margin to knock at higher loads/RPM. My 14 FXT CAN run on 87, but the owner's manual acknowledges that you'll experience knock and that it's normal. Normal my butt. I'll run 93 octane, thank you very much. Even on 93 octane, tuned to Stage 1 (ECM tuning, no mods), my data logs STILL show knock and occasional lowering of the Dynamics Advance Multiplier (DAM). This engine is also boost-happy (twin-scroll), so that margin to knock should also be a requirement, IMO.

I've tried higher octane in my 2.5 NA Legacy and didn't notice any butt-dyno improvement or gas mileage increase. It's a sedate A-to-B mobile that I rarely take to WOT/high RPM, so even if there were some beneift at high engine RPM/load, it wouldn't be worth it. I'll let the ECM retard knock a tiny bit during those conditions.