Interested in what fuel people are using. Tried a search so I don't think this has been discussed previously. So, is it the cheaper grade or more expensive and what really should be used in our cars and why - does the more expensive give better mileage or performance or just better for our engines or what?

Here in UK, we have the RON grade (95 or 98). I think you guys have a similar (PON?) which is equivalent but numbering system is a little lower - same fuel though.

I am using the cheaper, but should I???

 

doesnt your gascap/fuel door/gas gauge say Premium Unleaded Only? Or whatever you call the highest grade there. Lower octanes can make the car ping and just not run as good as it should. Most high performance, especially FI cars are Premium ONLY not recommended.

 

its recommended to use premium as in our manuals

 

premium would be better but u dont need to use it it wont cause damage

preimium is better if u drive fast or race at the track and more mileage

 

It has been discussed many many times. The short answer is use what is recommended in the manual.
Here's explanation on octane: http://autorepair.about.com/od/engin...m?terms=octane

It all has to do with combustion. the higher the octane the less detonation/ping/knock you will have. i'm too tired to give a detailed engineering explanation, but howthingswork.com should explain it also.

 

Here are the search results:
https://g35driver.com/forums/search....archid=2149529

Here's a couple of threads:
https://g35driver.com/forums/showthr...ight=grade+gas
https://g35driver.com/forums/showthr...ight=grade+gas
https://g35driver.com/forums/showthr...ight=grade+gas
https://g35driver.com/forums/showthr...ight=grade+gas

 

Very nice... saved me the time to do this for him lol. In the Manual it says we should use Premium Unleaded Gas which is what i use.

 

Not sure about the UK but over here there is only about a 20cents difference per gallon from the cheapest to the most expensive. I know I read it on here before, I was using mid grade for a while but the argument made on here was, the difference between the good stuff and medium is really no more than 3 a fill up. What is 3 dollars to get the best that is offered really? Especially when it is what Infiniti is telling us to use?

 

Thanks for all the replies and those that managed to find information through searching, when I could not. I'll start using the premium (98 rated in the UK) from now on. There is a sticker on my fuel cap but of course it is in Japanese (as is the manual) - but I should have guessed at checking the US manual which I do have a PDF of.

 

Ok i beleive premium gives better gas mileage....But it could just be differences in my foot. Fill up premium and if you are poor when you drop down to a lower grade you will think you are doing a justice to your wallet...Well enough for a sub or something

 

For those UK drivers, I found the following table of use:

RON MON PON
90 83 86.6
92 85 88.5
95 87 91
96 88 92
98 90 94
100 91.5 95.8
105 95 100
110 99 104.5

Our american friends use PON, we use RON.

 

Repeating myself again, but Sport Z magazine did a dyno comparison with a Murano. First running it on 87 then 91. Mileage was down only 1mpg on 87, but HP at the wheel was down 10%. You believe most everything else in the manual why not the fuel recommendations?
I suppose if you have a lower compression, economy car and the manual said you could run it on 87 just fine, some folks would run 91 because they think it's better if it costs more.... go figure.

 

92-94 octane super unleaded + 1 can of seafoam # sf-16 once a month...

 

I switched over to Shell V-Power. Do you guys get that over there?

A bit of a burning clutchy smell after some launches. Probably needs to get used to the higher octane fuel, what d'you reckon?

 

Who cares about dyno or performance is it safe to run on 89 without car problems????