Audi R8 Forums banner
1 - 16 of 16 Posts

·
Registered
Joined
·
347 Posts
Discussion Starter · #1 ·
I haven't got the English manual yet so not exactly sure what is wrong and am currently basing on what my dealer told me.

I picked up the car yesterday and I filled it with normal unleaded petrol then the engine light went on. I was then told that the normal unleaded patrol is not good enough for the R8 and the sensor in the R8 is very sensitive. Having said that, he told me I can just funish with the normal unleaded but just remember to fill it with premium unleaded in the future.

Anyone had similar experience? Is it really OK or should I just drain the petrol from yesterday?
 

·
Registered
Joined
·
172 Posts
I will not claim to be an expert on the subject but I have a very good friend at BP who is a chemical engineer and in his opinion the qualitative differences between regular and super unleaded fuel are minimal. Having said that there is a direct, albeit slight, correlation between octane count and the maximum engine output which is why performance car engines are specifically calibrated for higher octane fuels.

German high performance cars used to be calibrated for 98 octane fuel but the highest octane available in the US is 93 (many years ago you could still get 96) so over the years most high performance cars have been calibrated for lower octane fuels for worldwide use.

I would recommend adding super as needed to supplement the octane levels in the regular fuel; draining seems overkill but is also an option. Perhaps it will give you greater peace of mind but I cannot imagine any damage resulting from the regular fuel.

I am less familiar with octane additives but these are also available. I would tend to be more weary of adding any fuel additives unless you are advised to do so by someone who really understands their contents.

Hope this helps. If nothing else I am sure it will solicit other responses.
 

·
Registered
Joined
·
367 Posts
Dude, you probably spent like $200k on your brand new R8 and you're filling it with REGULAR?
(doubt it would trigger the CEL - I'd have the dealer diagnose)
 

·
Premium Member
Joined
·
1,034 Posts
My biggest concern would be your too quick to "B.S." dealer! IMHO, no way a tank of regular should set off the check engine light. Unless the R8 has sensor capabilities far beyond any road car I've ever heard of, the ONLY way your car ('s engine mgt. sytem) could know what octane fuel you have onboard is by the knock sensor detecting detonation. Since this can, sometimes, occur even with high octane fuel, under the right combinations of load and atmospheric conditions, etc., it would seem HIGHLY unlikely that the engine mgt. system would send up a fault code ("check engine" light) for a little bit of knocking. Retard your spark timing a little, maybe, with a slight loss of urge, but I would agreee with 996 that you need to have your dealer pull the code and see what's up. Incidently, you see the premium pumps in Europe today labelled "98" but that is a DIFFERENT octane measurement (RON) from what you see here. Our fuel is labelled with the average of the Motor and Research octane numbers. Our 91-92 premium on the west coast is very likely about equal to the European 96. And I wonder if it might be even better now with the mandatory 10% EtOH we have, since ethanol is a great knock suppressor. But they probably just take advantage of that to use a lower octane mix to begine with!! With a high pressure turbo car like my Volvo R you really pay attention to octane, because it translates directly into performance (and your butt dyno feels it!) much more than with a naturally aspirated engine. My Volvo R loves 10% EtOH, but it definitely steals 2 mpg. off the mileage.
 

·
Registered
Joined
·
347 Posts
Discussion Starter · #5 ·
Thanks for the advise bro! I should have it checked soon!

Yes, my fault that I filled it with regular. Felt like being cheap yesterday. Then again, when I was in HK I also mix the regular with premium, which seems to work a little better than when I just use premium.
 

·
Registered
Joined
·
96 Posts
Thanks for the advise bro! I should have it checked soon!

Yes, my fault that I filled it with regular. Felt like being cheap yesterday. Then again, when I was in HK I also mix the regular with premium, which seems to work a little better than when I just use premium.
800, in HK the regular and premium are 98 & 100 Octane and the additives so there are no real difference. Hope you sort it out soon.
 

·
Registered
Joined
·
718 Posts
Sorry guys,

Must disagree !!!!!!

Cannot comment on the engine light. Sounds highly unlikely to be fuel though.............

The European manual states the car can run on 95 RON "unleaded" or 98 RON "super unleaded".

We cannot get 100 RON over here (it is a specialist racing fuel).

91 RON should not be used (but can be used in emergency only for short distance and at lower engine revs).

As noted RON and US Octane numbers do NOT correspond. You need to check as to which standard your country uses.

My car is fuelled mostly on 95 RON and works well, there is a small (barely perceptable) difference in performance when I use 98 RON. On the track I have used both and do not notice any difference at all.

USA: Note that in UK 98 RON is much more expensive than 95 RON - about US $0.80 MORE expensive per US gallon.
 

·
Premium Member
Joined
·
888 Posts
Re: Engine light on?! ..Octane ratings

For those really interested I have pasted below an summary (from Wikipedia of course!) which explains the Octane ratings in US/Canada and the rest of the world. I was confused about this when I saw that my R8 (US) has a label requiring 98 RON whereas our gasoline (petrol) pumps provide "93" which turns out to be acceptable because it is "93 (R+M)/2"

Octane Ratings:

The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing these results with those for mixtures of isooctane and n-heptane.

There is another type of octane rating, called Motor Octane Number (MON) or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load. MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, a higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON. Normally fuel specifications require both a minimum RON and a minimum MON.

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).
 

·
Premium Member
Joined
·
1,034 Posts
Re: Engine light on?! ..Octane ratings

Swansailor pretty much covers it. As I said in my earlier post, our US 92 is probably about RON 96, and on the West Coast that is as high as you can get. Union 76 (before their marketing arm was bought out by somebody, BP I think) used to have a RON (I think is how it was rated) 100 Racing gasoline that they marketed spottily. At PIR raceway in Portland, the Union76 station across from the entrance used to carry it--and sell a ton of it on club race weekends. But that is gone with Union getting out of the retail business (still see the "brand" but it's owned by BP or someone now). I understand that one of the marketers (I forget who) in the Central and Eastern states still carries a "high octane" fuel that's something like R+M/2 95 or 96. You guys who can get RON 100 are lucky.
 

·
Registered
Joined
·
293 Posts
800. Where did you put the gas in? I was out of Seoul in my previous E55, and one gas station put in "fake" gasoline into my car. Usually, when the gas fill-up takes longer than usual, it is most likely fake gasoline they are putting in your tank. You gotta watch out for those. Usually the chances are almost impossible to run into a gas station that does that, but it happens. I never thought it would happen to me. I highly suggest you gas up at Kazen near Apkujung on Dosanro. Although slightly more expensive, their premium is a higher octane than the premium in other gas stations.
 

·
Registered
Joined
·
347 Posts
Discussion Starter · #13 ·
800. Where did you put the gas in? I was out of Seoul in my previous E55, and one gas station put in "fake" gasoline into my car. Usually, when the gas fill-up takes longer than usual, it is most likely fake gasoline they are putting in your tank. You gotta watch out for those. Usually the chances are almost impossible to run into a gas station that does that, but it happens. I never thought it would happen to me. I highly suggest you gas up at Kazen near Apkujung on Dosanro. Although slightly more expensive, their premium is a higher octane than the premium in other gas stations.
I filled up in the GS Caltex at Hannam. I didn't think they will have fake... but thanks for the advice.
 

·
Registered
Joined
·
293 Posts
Did you get a license plate? I still haven't gotten mine. :mad: Also, what extras did they give you so far? I was promised a car cover, but still nothing .....
 

·
Registered
Joined
·
347 Posts
Discussion Starter · #15 ·
Did you get a license plate? I still haven't gotten mine. :mad: Also, what extras did they give you so far? I was promised a car cover, but still nothing .....
Just before I left, I registered myself at my friends' place. (aparently it's pretty easy for foreigners) My wife told me that they are getting me 8888. Not really something I wanted 100% but not one that I would complain.
 

·
Registered
Joined
·
347 Posts
Discussion Starter · #16 ·
Umm, forgot to answer. I got 2 umbrellas, golf bags, all sorts of useless stuff.
 
1 - 16 of 16 Posts
Top