your engine is desgined to run off premium gas if you use a lower octane the engine can start knocking and can cause damage to your engine so basicly use 91 octane cause thats what your suppose to put in your car.

 

if you use lower octane, your engine will knock. in order to stop the motor from knocking,your knock sensor will "sense" the knock, and will tell the ecu to adjust or "retard" the timing and probably some other things. reducing fuel economy and power.

 

Yes premium is better for your car but you have 2 take into consideration about the altitude and how cold it gets. not going into the science in it, were you live will have regulated the fuels octane level for you so you dont have 2 worry about anything.

 

Normally I wouldn't have a problem running regular at times with my other vehicles since 91 octane is recommended but not required, but the gas lid on the G says premium unleaded so I assume premium is required so I'll run premium. I also agree with nutt, altitude is also a key factor. The higher up you go, the less octane requirements will be needed due to the fact that the thinner air effectively reduces compression ratio.

But until someone produces real-time data from an OBDII reading in the same route for premium vs. regular, I think my opinion is as correct as the next person(s) opinion

 

How about running 100+ octane racing fuel

I also wonder if boosting the octane with treatment(outlaw, etc..) is worth it or just a waste.

 

double post

 

again, using lower octane fuel on our G will force the G to run at a lower performance mode... Our G has "advanced" timing for performance. Advanced timing requires higher octane. Using lower octane will cause "detonation".

Which in return, produces "knocking"... Every car with an ECU has knock sensor. Once the knock sensors feels or sense any knocking, it will retard the timing to prevent the knocking.

Which is what it is suppose to do.. If you use higher octane, the ECU will advanced the timing by itself for increased performance and fuel economy.

I really dont see why anyone would use lower octane on the G, just so that the ECU can re-tune the G to run like a civic. (Overblown, but yeah).

 

The octane boosters dotn really help if u read hte label it "can" increase oct by "up to" 5pts. which is .5 so say u fil up with 91, and u put in 1 bottle in u "can" get up to 91.5 so u would need a good 4-5 bottles for it to bump up to like 93.

 

im jellous if all you on the east coast u get 93 oct at the pump here in norcal we get umm 92 i think or 91 max.. if i drive a hr away there is 1 place that sells 100oct. as well as higher. but your going to be paying 6.00/gal give or take .50cents.

I read the manual and it mentions use premium at all time unless its not available then use mid grade but never fill fully up with mid grade, fill up enough to get you to a destination where u can put prem. so i assume u could to 50/50 blend of prem and mid grade but saving an extra 2bucks from mid grade to prem (biased on if tank was empty on a full 20gallion fill up, with prem being 10cents more) isnt really worth it imo... I guess driving such a nice car has its down side of gas i remember my old civic and integra i could put the cheap stuff and fill up for about 20-25 and last me like 2 weeks. in the G its a 45-50dollar fill up and lasts me 1-1.5weeks lol.

 

its like an extra $3 a tank, just use it

 

OK, sorry for bringing up a rather drug out thread but here is my question. I read through the first five pages of this thread and not once did any one bring up the point that in the owners manual it states that you can use regular unleaded in the sedans but premium is required in the coupes. If all the G35s are the same then what gives for this statement? The only thing that comes to mind for me is that the computer tune must be different in the two cars. Maybe I missed it by skipping to the end after the first five pages but could someone shed some light on this for me? I know I don't always but premium in my G35 but if I don't i will only go down to unleaded plus. I have never put regular unleaded in mine yet.

 

ah srry if this was addressed guys. but iv been putting 89 in my baby (out here in cali only have 87-91) and i was told by the dealer i bought it from (non infiniti) that 89 would be fine, so is 89 fine for my baby? and if its not, i wouldnt mind switching to 91, but if i would, how would that work?just run this 89 till empty then put 91 or what? just wonderin so i dont mess my car up

 

just switch over to 91... No need to run it till empty

Is is a fact or myth that different gas stations have different quality fuel? Example. Is Walmart's gas less efficient than Chevron's gas? I wouldn't have thought so, but a few people have told me otherwise...

 

stop being so cheap its a G not a freaking pinto

 

So, yeah...the crooks in the oil industry are banging us up $.21 cents tomorrow. So, this begs the question..can I put regular in without harming the engine? Im sure I may see a bit of a power depletion..but at $4.00 Fing dollars a gallon.. I need to start cutting costs...and 87 or 89 is the way I need to do it.

What do you guys think. Will I hurt anything by downgrading my octane??