Aight. So I finally ran the numbers (I record every fuel fill up)
And I got strange results:
When I got the car i started using 87 Octane gas - I got ~19mpg (12.5L/100km) I drive only city so, that looked normal and was exactly on the dot with what the owner's manual said.

Now, after running it with 87 for ~1500 miles I switched to premium (91 Octane) for 1000 miles. Got a little better mpg. But decided wasn't really worth the price.

Then I switched back to regular and just recorded my miles and liters put in. I've done 00vi since then also after doing 00vi got 225 tires. I figured the tires would bump up my fuel consumption a bit but I just ran the numbers and right after switching back to regular (87 octane) my fuel consumption FELL to about 14.7mpg! (~15L/100km)

So:
Pre-Premium - 19 mpg
Premium - 20 mpg
After Premium - ~15 mpg!
After 00vi - ~15 mpg
After Tires - ~15mpg

I am at a total loss as to what could have caused that.

 

how do you know it was down to 15 before the 00vi swap and tires?

 

why does everyone think these cars need premium gas its a maxima not a benz

 

It doesn't "need" premium gas. But it does run a little better since it was designed for higher compression.

Higher compression = may cause predetonation with lower octane gas = may cause knock. But they are equip with a knock sensor that will retard the timing to help alleviate knock. So... whatev

 

because the Maxima calls for it if you read the gas lid.

 

B/c it says use Premium Fuel on the tank lid? Either that or it says use 91 octane, I cant remember.

 

Its recommended that you use 91 or higher.

 

Either way, that means the engine was tuned to be used with higher grade fuel. And alota people have reported the engine knocking if you use below that.

 

"Premium fuel is recommended for maximum performance."

 

Why do newbies say stupid things?

Nissan designed the car, why don't you listen to them?

 

This.............

Pretty sad a newbie gets it... No offense smokey, but there been some peeps on this site for years and dont get this......

 

dont assume cause im new on this site im a newbie to cars, ive been doing my own work for a long time.

 

Just use the mid grade and it'll be fine

 

yeah, i've been using 89 for awhile now and since gas prices went up i have been mixing 87 and 89 and maxy's running pretty good. little lower on the mileage, but i dont care.

 

When you did the 00vi swap, did you use the 4gen or 5gen lim? If you used the 5th gen lim with the 5th gen injectors with out a true tune, you will run rich as hell

 

I couldn't have said it better.

 

Reading > You.

Win.





:Sprint:

Because a car that can go 400K with little or no problems just isnt enough for some people.

Why your post wreaks of ignorance?

Fail. Midgrade is just cheap **** plus a little of the good stuff.

93. FTW.

 

The ECU tries to maintain a 14.7-15.5 AFR during closed loop/part throttle/cruise based off of readings from the o2 sensors and the maf. When driving around untuned (10.0 AFR at WOT) with de-k injectors, my gas mileage remained the same as it was with the stock injectors.

 

89 is fine, but if you want to throw your money away, send it to me. i mean, these cars were built when 87 was the highest so we are using high octane like it was 1995-99...

 

??? I was able to get 94 octane all though the 90's and higher in the 80's and yes I also live in PA

 

now your running less mpgs with 89.. so you fill up sooner.... why dont you just spend around 10 cents more and put premium gas and run normal?

 

Maxima Owner's Manual says 91 octane or higher recommended, that's why. In all honesty, Benz owners also don't NEED to use premium fuel. I know a lot of people who put 87 octane gas in their S classes and have no issues with knocking or any other problems. However, the fact of the matter is, when you're buying a car, you follow the maintenance schedules, buy the recommended oil, etc. etc. based on the designers' and engineers' recommendations...so why exclude the type of gas you should be using?

For what it's worth, I have a 1995 SE and didn't have problems using 87 octane gas but I do get considerably higher mpg when I switched to 93 octane.

 

Thats what it says on the fuel door of my maxima, every time i use premium my car performs better, doesn't have to be a mercedes to use better gas

 

^^ What he said ^^ 4g is suppose to use premium gas to perform good.

 

Now that's over.

Because of stupid **** like this that such valuable assets as pmhor are no longer around, and a good majority of the 4th gen'rs only come in here occasionally.

To op, wish I could help. But I haven't done my 00vi yet.

To everybody that wants to run cheap gas to save 10-20 cents, maybe you should've thought about that before buying a V6 sedan, that was and always has been touted for being sporty I'll just blow on past ya while you try to figure out why you can't keep up(fyi; it's because you have a knock. Should really get that checked)





















:metalmax: please

 

I think it's funny watching newbies trash other newbies. It's about all the joy I can get out of a worthless thread like this.

OP, I don't have a '00VI either but I am running 225 tires (on '06 18" wheels) and I average 22-25 mpg running nothing but chevron or texaco premium 93 octane dino juice. Maybe you need a tune-up?

 

You calling me a noob?

That's pretty good, my 4th gen is a 5spd, egr delete, fed converted, and catt ypipe. I usually average 22-24. Those murano wheels? Wish we could get 93
My 5th, auto and stock, I get about 20. But can knock it down to 17 or so really easy.
If it ends up just being routine tune up stuff, I dare say it's going to be a lot of tuning up.

 

i only said you dont NEED premium gas not to say its not a little better, but ive been running 87 for about 7000 miles i dont get knock,and i get 26-28mpg on the highway so why pay more for gas when the car runs perfect, gets good mileage how much more mpg is premium gonna give. and the performance is still good, in all honesty its a 99 daily driver that i got dirt cheap and fixed so i dont have to drive my gas hog 6.0l truck, its not worth it to me to use premium. if your cars has alot of performance mods then premium is good for you, whats good for some isnt good for all just saying

 

so, its 3.89 for premium right now as apposed to 3.49 for regular and 3.59 for plus. a dime hunh?? i agree that cheaper gas doesnt allow our cars to run as effeciently or as well as a higher octane but i only put 25.00 dollars worth in at a time and i have a new fuel filter and plugs as well as i just did upper intake clean so she runs really well. plus does fine in maxy, but today she gets a treat. im gonna fill her up with premium. and, i agree withe noob above ^^^^, op with performance mods probably need/want higher octane but im running strictly stock.

 

No

 

OP, i think you have an issue that has absolutly nothing to do with the type of gas i think that since you are using the "required" fuel you are now noticing it

check your knock sensor with a scantool (check pending codes)
and clean your maf


And for everyone else that has molested this tread,
an engine will run on anything combustible that doesnt mean its good
i can run an engine on nail polish remover but never my max maybe a weed wacker but either way its not a good idea its not a civic

and imo mercedes sucks poor grandma stying, under powered engines, and hugeprice tags

 

Holy moley! I check out for a few days and then find out I started another massive thread with almost no useful info!

I record every single fill up I do. Amount in fuel down to 2 decimal places and exact number of KM on the the odometer. I currently have records for my car for the last 12,000 km. (which is since the first day I had it) Whenever work gets done on the car I also note at what KM it was done in the same log.

Considered that before doing the 00vi, therefore I'm running 4th gen lower with the 4th gen injectors.

Thing is, the mpg figures went down immediately after I switched from premium to regular. Like literally on the next tank of gas.

Also, in the Canadian Owner's manual it just says to use unleaded gas. Nothing about premium. Though maybe because gas north of the border is generally better?

Either way. I'm going to try going back to premium on my next tank and run with premium for the next 1000km or so. Hopefully it will bring my mpg back.

And off topic:
Well, a 1997 6L V12 Merc engine produced about 400 HP. Which is exactly double power for double displacement over our engines. =P So do you suggest that our engines are also underpowered? (And FYI that 400 HP is with a rather restrictive intake system that was put in there to meet US emissions standards)

 

how much does it weigh???
going fast IS NOT about high numbers its about the power to weight ratio


and that was just my opinion if you like it by all means buy one but i will not be doing the same

 

This guy's got it

 

does anyone know how to turn off check engine light for misfire? And do you have the code for the obd?

 

buy a damn code reader, delete the damn code..

 

Damn noobs..... SEARCH.... SEARCH

Goto the stickies, find the "How To's" and find the guide on how to check the engine light using a screw driver and the ecu.......

 

Go to autozone or advance auto parts and have them read and delete the code.

 

FIX IT!!!!!!!
the light will go off on its own

 

Yeah, the MIL isn't there to annoy you.