Petrol type for 370GT

[nzrhysco]

Hi guys

I've seen a couple of threads on this subject but none that answered my specific question. I've had my 2009 370GT (7 speed auto) sedan for over 3 years and 20,000km now and ever since I bought her I've only ever used 91 petrol (the same as I did for my V35 300GT) because I never did any investigating. I have never had any problems running on 91 - she runs smoothly and perfectly, does 0-100 in 5.5 sec, no pinging, rough running etc, and I can consistently get over 600km on a tank with a motorway, city, cruisy and wheel spinning mix of driving. It was only researching about doing an oil change  myself (and downloading a US Infiniti G37 manual) that I came upon the concerns about using the wrong fuel.

Is it okay to keep on going as is or do I really run the risk of damaging the car?

Cheers

 

Edited July 17, 2018 by nzrhysco

[GTofuS-T]

It's fine, US petrol is is like dirt water, our minimum octane is like premium over there... In an n/a factory tuned application you won't have any issues. The only benefit (as far as I'm aware) of using 95/98 in an n/a is some additional cleaning additives

[niZmO_Man]

Would anyone know what the Japanese V36 are tuned for? 98 RON? Maybe 95 RON?

North America uses AKI while we use RON to measure/advertise octane ratings.

91 RON = 87 AKI
95 RON = 90 AKI
98 RON = 93-94 AKI

https://en.wikipedia.org/wiki/Octane_rating

[GTofuS-T]

Trust the US to use a different rating unit ?

Some wise advice from the Oregon Dept of Agriculture: "Listen to your car’s engine. If it doesn’t knock when you use the recommended octane, then you are using the correct grade of gasoline." ?

[The Max]

The VQ37HR is a high compression engine and is built for 98RON. Don't cheap out on your fuel. Be sure to use the very consistent BP Ultimate.

[KiwiRS4T]

Try to get a 80 - 120 time (hold in gear so no gear change if possible).  Run your tank as empty as possible and then after a few fills . with 98 reset your ecu by disconnecting the battery for a few minutes and then repeat the test. I would expect a tiny increase in performance but would in any case stick with 98 where possible for the reason above (high compression engine).

[The Max]

...and my apologies. I missed the "V" in VQ37VHR. :P

[nzrhysco]

Thank you for your replies, but some of you are missing the point. The book says use 96+, so obviously 98 is ideal, but I have been using 91 for over 3 years with no loss of performance or economy or signs of issues with the engine. She has also been serviced by my local Nissan dealer. Essentially I want to confirm that if my use of 91 was going to cause any problems then it would have shown up by now. Is this correct?

Thanks

[The Max]

You are definitely suffering a loss in performance because the ECU is retarding the timing to prevent knocking. How are you so sure that you're not? The butt-dyno is not an indication.

Also, regular servicing doesn't mean you're preventing the effects of pre-ignition detonation from turning your cylinder bores egg-shaped prematurely. Unless you pull the engine apart, you won't know.

The point is, you know Nissan specify a high octane fuel. So why are you going against their instructions by using such a low octane fuel in the first place?

[nzrhysco]

My point is that I didn't realise I was using the wrong fuel. The cars done 35000km and Im only doing 6000km per year so I don't care if it reduces the total life of the engine as I'll be selling her before 50,000km. I just wanted to know if any issues or consequences are going to show up in the short- medium term, and based on my own experiences over 3 years, I will say probably not!

[The Max]

You're right about the short-medium term. At worst, perhaps blocked injectors over time because of the lack of reasonable cleaning additives in the fuel.

But now that you know better, hopefully you've made the switch to 98 octane.

[KiwiRS4T]

10 hours ago, nzrhysco said:

My point is that I didn't realise I was using the wrong fuel. The cars done 35000km and Im only doing 6000km per year so I don't care if it reduces the total life of the engine as I'll be selling her before 50,000km. I just wanted to know if any issues or consequences are going to show up in the short- medium term, and based on my own experiences over 3 years, I will say probably not!

So why bother posting? If you want to learn something (you could share with us) do the back to back testing as above.

[nickcorr]

Also interested to know what book said 96+ octane...

Personally have run all my imports (including my KV36) on 98 octane, and glad for the cleaning packs that have helped keep the engine and injectors nice and internally clean.. I also do low mileage like you and therefore have less of a concern about fuel prices and consumption and so can enjoy my car.. :-)

[admS15]

I heard these love diesel.

[niZmO_Man]

C16 is best

[The Max]

Mine prefers methanol with a dash of Tabasco sauce.

[meatball]

it seems you have answered your own question long before posting here

 

[doggido]

What about bio fuel?

I've been putting 98 in my tank & apparently it is a bio fuel. Would that make a difference?

[Ben C34]

34 minutes ago, doggido said:

What about bio fuel?

I've been putting 98 in my tank & apparently it is a bio fuel. Would that make a difference?

What 98 is a bio fuel?

[niZmO_Man]

Biodiesel is biofuel. Ethanol blended fuel (E85) would be sort of bio fuel.

But then, petrol is refined oil out of the ground, which used to be tiny creatures hundreds of millions of years ago. So you could say all oil based products are "bio", sort of?