Jump to content

What can happen if you run your Zed on 95 Ron.....


glrnet

Recommended Posts

I was at Abbey today and Tony showed me a piston from a 350 (sorry don't remember the year) that had been run almost exclusively on 95 Ron unleaded fuel, please don't do it guys, it's going to hurt your engine AND your wallet eventually................... :wacko::surrender:

 

~edited to make clear this was use of 95 Ron almost exclusively

 

photo-2-1.jpg

Link to comment
Share on other sites

Its ok to use 95RON so long as you drive like a granny. Everything will be fine until about 5K RPM when the knock sensor decides not to play any more. So for when you are stuck dont be scared to use it, just drive it like a Diesel while you have it in and then make sure you get Super in there ASAP.

 

Stickied as this is proper proof :thumbs:

Link to comment
Share on other sites

Good point well made Chris, have edited my original post to make it clear that this damage was caused by using 95 Ron almost exclusively. :thumbs:

 

Its ok to use 95RON so long as you drive like a granny. Everything will be fine until about 5K RPM when the knock sensor decides not to play any more. So for when you are stuck dont be scared to use it, just drive it like a Diesel while you have it in and then make sure you get Super in there ASAP.

 

Stickied as this is proper proof :thumbs:

Link to comment
Share on other sites

In The States which is the largest market for Zed's in the world its extremely difficult to find anything above 95 RON and if you do it costs $7-8 a gallon. 95 is the premium grade there. In some of the Mountain States for example Colorado you'll struggle to find anything above regular which is 91 Ron :scare: .Maybe this is why so many U.S owners had engine problems on their MY06's :shrug: . In Japan, the home of The Zed 100 Ron is recommended :wacko:

 

 

Pete

Link to comment
Share on other sites

what happens if you put 97+ ron in a shed though - obviously built and designed around 95 Ron

 

(mods - move this if you like) :blush:

Nothing, depending on when said shed was built. The extra resistance to detonation of 97RON over 95RON would be wasted as the car would not run as high a compression. So the car would always fire the spark before the fuel to reach det prematurely. So unless it has higher compression and can alter ignition timing then its pointless. If it can use it then you'll get slightly higher MPG as the fuel is burnt more efficiently than 95RON.

Link to comment
Share on other sites

Pete - I dont think the different "RON" ratings are comparable though are they? I think 95RON in the US is equivelant to our 97RON and that is equivelant to 100RON in Japan?

 

 

No, they use Aki ratings in the States and the maximum AKI available is 91, the equivalent of 95 Ron.

 

280px-Gas_Station_Pump_Five_Octane_Ratings.jpg

 

No idea about Japan though :shrug:

Link to comment
Share on other sites

No, they use Aki ratings in the States and the maximum AKI available is 91, the equivalent of 95 Ron.

 

You can get 93 (at least) over there, which is the same as our 98 roughly.

 

I'm surprised that that piston failed - the ECU should have switched over to the low octane maps and prevented knock from occuring - obviously that didn't happen in this case.

  • Like 1
Link to comment
Share on other sites

I'm surprised that that piston failed - the ECU should have switched over to the low octane maps and prevented knock from occuring - obviously that didn't happen in this case.

The knock sensor only works up to 5kRPM in the 350z, so even on the high det map, its long been assumed the car can still kill itself if highly reved with 95RON in it. In fact I'm pretty sure Mark@Abbey had one on the dyno that was knocking like mad before he mapped it for 95RON. Thats why the owners manual says not to rev it above a certain amount of revs when you use 95RON in an emergency. I beleive it also states to get Super back in there ASAP.

Link to comment
Share on other sites

I'm surprised that that piston failed - the ECU should have switched over to the low octane maps and prevented knock from occuring - obviously that didn't happen in this case.

The knock sensor only works up to 5kRPM in the 350z, so even on the high det map, its long been assumed the car can still kill itself if highly reved with 95RON in it. In fact I'm pretty sure Mark@Abbey had one on the dyno that was knocking like mad before he mapped it for 95RON. Thats why the owners manual says not to rev it above a certain amount of revs when you use 95RON in an emergency. I beleive it also states to get Super back in there ASAP.

 

The ECU will only react to knock up to about 5.2k - if it knocks a lot in that rev and load area the ECU will switch over to the low octane maps which have around 2-3 degs less ignition advance. So you still get less advance over 5.2k if the engine is in high knock mode.

 

The amount of knock required to get the ECU to switch to high knock mode is still quite significant - so damage could be done before the engine switches maps. Also, pulling 2-3 degs out of the ignition map isn't really that much if you're going from 99 to 95 RON fuel.

 

I've attached a screenshot of the knock window - you can see rpm in the y axis and engine load on the x axis.post-5210-135011918693_thumb.gif

 

So, I agree - run the car on 98/99 RON and if you have to run 95 then drive gently and refill with higher octane fuel asap.

Link to comment
Share on other sites

No, they use Aki ratings in the States and the maximum AKI available is 91, the equivalent of 95 Ron.

 

You can get 93 (at least) over there, which is the same as our 98 roughly.

 

You can find 93 and in some cases even 94 in the big cities or near to refineries but the areas I've been to its usually 91 max.

 

I'm surprised that that piston failed - the ECU should have switched over to the low octane maps and prevented knock from occuring - obviously that didn't happen in this case.

 

 

Would be interesting to know what engine this came out of, I would imagine the high rev 06 and onwards engines would be more likely to have this problem. I'd also like to point out there are more things that can blow a hole in a piston than duff fuel ;)

 

 

Pete

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...