well i bought my car from my sister who had it from new in 2000 to 40k and she used nothing but reg gas in it without any problems. i bought it and started useing plus up to 70k and just recently over the summer with gas prices out of line started using reg. i didnt put 2 and 2 together immediately and she developed a type of knock. i took her to my mechanic and asked 2 other mechanics that i know, who all looked at me like i was crazy when i suggested it may be due to the type of gas i was using, yet none of them could explain the the noise.

But then again they dont know the power of the org lol . which is where i got the idea that reg gas could even cause a problem to our cars . which by the way guys as i said , every mechanic i talked to said that was a ridiculous idea.

Anyhow i took it to sunoco and got a fresh tank of their super primium (i think 93) gas and about half the noise went away!!!!

now for the questions, why didnt it go away completely? Did i do permanent damage by using regular gas, not likely i think but what do you guys think? Are there any parts specifically are harmed by reg gas that can be changed easily? why didnt my sister have probs using reg gas for 40k. and i cant believe our maxs are such lil beothes that a lil reg gas will hurt them, what do we have beemers or maxs lol jk. any help is appreciated , thanks

 

Takes a few trips and a few tanks to get the knock gone. There are "knock" sensors that auto adjust for that. If your sister ran regular has for that long, the car adjusted for that grade of fuel, when you put some of the good stuff in it, the car needs to readjust for it.

 

yeah all Maxima requires premium, not low octane gas cuz the EMC has to compentate for the compression to make a complete combustion.

 

93 octance pwns.

 

thanks guys, i filled up with sunoco super again and put the chevron techron in as well and the noise is all but gone. i'm going back to plus (91)next time, i'm hoping it will go away completely by then...if not, i'll just deal with it cause putting in super is just too expensive for my gas guzzling max.....

 

Pour some injector cleaner in there while you're at it. Might as well clean up that junk you and your sister have accumulated in 70k miles by using crap fuel.

 

Maxima is rated for 91 octane. 91 should be fine, no need for 93. I only use 93 because there is no 91 in my area , except maybe some sunoco stations which charge about 2 cents less per gallon of 91 than 93.

 

Gas Guzzling max? Hmmm, the gas/money equation. Let's see an example:

Say premium or high octane gas in your area has a price differential to the low octane gas of .25/gal. and your Max holds 18 gallons of gas. A tankful of the high octane would kick you back $4.50 more per tank. We can assume economy of 24 miles/gal. - meaning a tank allows you to drive 432 miles. If you drive 15,000 miles/yr., you're filling up 34.72 times.

So the extra cost of filling with premium is $4.50 (more per fill-up) x 34.72 (tankfuls per yr.) = $156.24 ...in a year. Or $3.00/week or .42/day.....

Doesn't seem like much to me, and sometimes I drive to a different station to save $.5/gal.!! Something to think about when your cars knocking.

 

WELL said., I'm not going to try and check your calculations. But, I do agree. It's not worth the hassle. Just do 93 or 91.

 

ur wallet that is

 

I wish. My BEST thus far has been 22.13

Heavy foot I guess. Either way, for all the money people dump into their cars, the extra cash it costs at the pump (I usually put in around 15 gallons at an extra .24 a gallon = $3.60), isn't nearly too costly for me to risk messing up my car.

 

I am surprised no mechanic you went to has heard of this... its pretty common knowledge, even my dads 99 escalade with a pretty standard chevy 350 needs to use premium when he's towing something heavy or else the engine will start to knock when pulling up hills.

 

waht exactly does knocking sound/feel like?

I run 87 octane w/ no ill effects... I tried 91, for like 10 tanks but i felt no difference... car runs fine w/87.... even when I redline it...

hmmmm....

 

if u have it ull no it as its pretty obvious
if its not broken dont fix it so leave ur car alone and b happy u can get by with reg gas

 

This type of logic baffles me. What do you think high octane fuel is any cleaner than regular fuel?

All fuel sold in America has detergents. Gasoline itself is a very strong solvent. There's no junk built up from using regular fuel.

High octane fuel is only better for some engines because it doesn't detonate (or explode) under lower temperatures and pressures. So the knock you hear is actually something called pre-ignition where the fuel combusts before the piston is in full compression stroke.

 

And any mechanic that doesn't know this and doesn't see it as an issue with higher compression engines isn't a mechanic you want to be bringing your car too much longer, he's a little

 

If you're knock sensor is working, you shouldn't hear any knocking on regular. It will lose power and mpg, but should not knock and ping.

 

$3.00 per fillup >>>> $2000 for an engine

Your logic is stupid

 

You bring up a good point. But you also have to factor in that with higher octane gas, you will get better gas mileage becuase the gas doesnt "pre-detonate" which causes the knock in higher performing engines. I had a 97 altima and go around 20 to 30 more miles per tank with 91 to 93 compared to 87.

The knock should go away, and as someone else said, put some fuel injector cleaner in there and stay away from ethanol. just my two cents.