LOL, nice try Max but the truth is that you didn't say anything of value in your previous post and as usual trying to take credit for someone else's knowledge. BTW, who is the we you are talking about? Go back to your corner troll boy.
Nice try at avoiding an apology TBone. You ranted all over against me saying I didn't know how engines worked. Who gives a rats ass about credit. Is that what this is all about to you? Fact is, you were wrong and are not big enough to apologize for your long winded rants.
What is it exactly that I'm supposed to apologize for Miles?
lol. Figures! Rant away then claim you're clueless.
Thats correct, to a point. While I didn't contribute to the subject, I did tell you to shut up. Thats got plenty of value in several peoples view, I'd bet on it.
Rubbish. I did nothing of the sort. I told you that you didn't understand octane, and the guy with the knowledge proved exactly what I said, you hadn't a clue.
I bet Miles at the very least is part of the "we" that deserves an apology for the crap you spew.
LOL, speaking of PKB....
Your turn!!
Suddenly, without warning, TBone exclaimed (09-Jun-05 6:33 PM):
TBone, thank you for this. I may not be a mechanic but this is exact sort of explanation I was looking for - con *or* pro. I missed it originally in some of the, uh, excess posts my question has engendered, and I've still to catch up with what is below, but the wording in my manual does indeed specifically mention octane ratings. I don't have it in front of me, but seem to remember it suggested using fuel with no higher than 87 octane. 95's a bit beyond that.
For those who happen to disagree, please post an explanation as to why not, unless you have already and I just haven't made it that far down the thread.
'Course, at the moment the question's moot. The garage closed the next day, due to receiving a possibly contaminated load of fuel - just-fueled vehicles started sputtering nearly immediately after leaving the station, from what I hear.
jmc
Suddenly, without warning, snipped-for-privacy@sny.der.on.ca exclaimed (11-Jun-05 9:20 PM):
Ok, so assuming this is true, how would I figure out if this particular fuel is safe?
jmc
Suddenly, without warning, snipped-for-privacy@sny.der.on.ca exclaimed (12-Jun-05 2:30 AM):
Ok, now I'm getting a bit lost. In your opinion, if I use "Premium" high octane (95) fuel (whatever formulation they use here in the UK) will there be damage my engine, whether it runs rich, lean, or within specs?
jmc
Suddenly, without warning, TBone exclaimed (09-Jun-05 6:47 PM):
Not sure, really. I purchased it overseas, it was built in Detroit, delivered to Montana, and registered in Virginia. They did ask where my residence was, so I'm guessing it meets VA emissions standards, but then so would a vehicle built to the more rigorous CA specs, right?
Anyway, though some of it was over my head, I did enjoy the actually informative posts in answer to my question (could have done without the more numerous name-calling posts, but then that's usenet), though I'm still not sure if I should use the fuel or not. I think I'll probably just use it to top off, since gas coupons are for specific liter amounts, and thus rarely fill the tank, unless I'm willing to take a loss.
Just so I understand, if I pump high octane fuel, it burns slower, and may cause the engine to think the mixture's too lean, and make it richer, right? Which, if I understood, could cause some sort of cycle where the mixture will rapidly cycle between too lean and too rich. It's unclear to me whether this will or won't cause knock or engine problems further down the line. I also don't know what would be the symptoms of such a cycle. I would appreciate your thoughts on this.
When I buy a vehicle, I buy with the intention of keeping it 'for life', so it is important to me that I not do something now that may not show as damage until some time from now.
So, thanks again, gentlemen (for the most part) for a very educational debate. Hopefully I won't start a whole new flamewar trying to get answers to these last few questions...Oh, and what is CAFE?
jmc learning something new every day :)
In my opinion? not very likely. If a car run on premium actually does run richer, driving it a bit harder (which most premium users will do by instinct)will help chase out any carbon build-up. If it runs lean, unless you are chasing it's tail very hard, you will not have an overheating problem - you may have driveability problems - but I doubt it. If it runs within specs, no problem.
You MIGHT end up with a damaged catalitic converter, but whether that would hapen significantly sooner than normal is rather doubtful.
Just my (somewhat educated) opinion on the subject.
Check the Specific Gravity of the fuel. If within points of 0.750 I wouldn't worry.
This cycle between too rich and too lean is actually the normal realm of operation of the emission system. All the O2 sensor can tell the computer (with the exception of a VERY few select non-chrysler vehicles) is if the mixture is too rich or too lean. Can't tell it how much too rich, or how much too lean - so it says "too rich" and the computer leans the mixture untill the sensor reports "too lean". The cycle repeats itself, and the average resultant mixture is stoich.
The number of "crossings" indicates the health of the O2 sensor.
cORPORATE aVERAGE fUEL eCONOMY
If you look on your keyboard there should be a button near the "Shift" key that has "Caps Lock" written on it. Push it. ;^)
Suddenly, without warning, jmc exclaimed (07-Jun-05 5:29 PM):
Just a quick followup. Turns out, I shoulda paid attention to the normal octane level of UK petrol - just got back from a 6-day trip, and turns out I've been putting 95 octane in my tank every time we take a trip. Oddly, the one gas station I use locally, has low octane gas. If there's a choice of one, it's always 95 octane. So, since I've been using it on and off for a couple of years, whatever damage is already being done. After this trip, I noticed a bit of knocking. I'll put lower octane in as soon as I use some of this up.
Is there any way to mitigate any damage already done?
Oh, and this'll put things in perspective, the next time you folks in the US cringe at the gas pumps: 6 day trip. 1,100 miles or so. Something in the line of $300 worth of fuel. ARGH! Last trip we take the Dak on. Rest of the tour, it's the 1991 Toyota pickup for trips.
There is no damage!!! The only danger there is, is from using less octane than required not more. I do not know how in the world people ever started thinking that higher octane will damage engine. That is bizzare!!!!
I suggest that you contact the manufacturer for an explanation since THEY are the ones putting this warning in the owners manual.
Did you see my reply? There are two ways that octane is measured, and three ways that the result of this measurement can be expressed. In the US we express it in the average of the two measurements, while continental Europe (and, I'll bet, the UK) express it as the higher of the two measurements. The odds are better than even that the "95 octane" you're buying in the UK is about the same stuff as "89 octane" in the US.
Matt Roberds
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.