Bottom line - my tuned VW loves 2.5 gal of E85 to a tank of 93, zero KR, zero drama, thing runs like a freight train. The tune I have is super-spicy w/r to timing advance (with more moderate boost) and I've found that if I want max performance/no drama, run a few gallons of E every tank. In winter on straight 93 (tuned for 93 but I suspect b/c they tuner is in Canada they calibrated this tune using a car running their 94) I can get enough KR to throw the car into limp mode. The ECU runs the mixture richer and richer to cool the cylinders as KR increases and at some point the fuel system physically can't meet the ECU's requested lamda so it pukes. E sorts it 100%.
Project Farm testing impacts of octane and ethanol content on power and mpgs...interesting!
- Thread starter TiGeo
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There is no reason highway cruising should net any more mpg on a higher octane fuel vs. low. You will make a little more power for sure. I collected data for 2 years on my Sportwagen and some of that was before being tuned and running 87 and 93, zero difference hand calculated mpgs. Same for our Atlas with many swearing up/down that running 93 nets more mpgs...never have seen it.
They don't go away b/c the urban legends and bad info surrounding this discussion continue to proliferate online. I know here at a normal station 93 is nearly $1 more per gallon than 87. It's unreal that folks will pay upwards of $15-20 more per tank to feel warm/fuzzy. At least at Costco the price difference is only about $0.30.
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BITOG: PF testing is straight trashJust like those who hate on PF, or look down their noses at @53' Stude who cuts filters, or those of us who buy oils the board hasn’t seen & we pay for UOAs, some people will hate anybody who’s doing things outside of THEIR comfort zone. I’m not saying PFs tests are always based in science, nor am I saying all the UOAs get accurate interpretations, but some people actually DO things, while others just criticize.
We should applaud the doers, and ignore the idle criticizers. JMO…
ALSO BITOG: posts with pictures of dipsticks wiped on paper towels to determine "things"
If he is testing drills, or grinders, or screws, or other hardware and basic tools, then his methodology for testing is usually OK. Sometimes, what he does, like breaking wrenches, makes for good video, but has little relevance.
When he tests oils, he uses specious methods that simply don’t translate into actual performance. He goes beyond irrelevance, into misleading.
And people who don’t understand how oil works actually ascribe some significance to his “testing” of motor oil.
So, no, PF oil testing isn’t allowed on BITOG any more. PF is that bad when it comes to testing oil.
I'd say it's beyond misleading into harmful. I know of 2 engines that suffered major failures, one of which I built, because the user followed PF's oil videos. "PF proved that Super Tech is just as good as Red Line, Pennzoil just as good as Amsoil and better than many others, so I don't need any kind of special oil." Then they come crying when they wipe the cam 50 miles into the oil change. I denied the one guy his warranty but offered to rebuild it for the cost of parts and machine work +10%. He didn't like that so I withdrew the offer and told him to take his engine to PF since he trusts him more.
In the 90's I did a few years in the insurance business. One client was an engineer for Texaco. I had a nice MK VII but it ran poorly with maybe 80k on it. He told me to use 5 tankfuls of Texaco premium in a row and then use Texaco regular after that. He said Chevron could be substituted, but only those two. At the time they both put the same level of additives across the board while all other brands put lesser amounts as the octane went down. The 5 premium tanks were to resist the pinging while it cleaned things up. Then I could go to regular which had the same amount of cleaning etc. additives but didn't need the higher octane by then to avoid pinging etc. He was correct. Ran like a top from then on.
If this were even remotely possible, Volkswagen would require premium to boost their mfr avgs w/r to CAFE.
Now, gather at a bare minimum 20 identical round trips on both fuels, and we can help you prove if there’s any statistical significance. My money is on zero difference, with possibly .2 improvement as a max.. but good luck.
Is it though? Some guys change their oil/trans fluid etc every five minutes for the same reason.
A higher compression ratio gives increased thermodynamic efficiency.
I log all my fill ups with lots of highway driving. VW openly said with the GTI that all testing including fuel economy and horsepower figures was on premium and going to regular would lose around 10hp. That didn’t change until 2022.
VW would have to test mpgs on the recommended fuel which has been 87 min for much of the MK7 run. They often will state power figures in the manual with a footnote that that power number was achieved using premium fuel.
It says premium fuel recommended and that regular fuel is ok.
Which year GTI?
the key to understanding the thermodynamics of high efficiency engines should provide info that quantifies the contributions of each of the engine features that adds to that thermal efficiency and describes the reasons for the improvements.
some of these can be gas recirculation, lean mixtures, high compression ratios, and rapid combustion. once each feature is quantified by its impact, the resulting thermal efficiences can be reported and the reasons reported.
some of these can be gas recirculation, lean mixtures, high compression ratios, and rapid combustion. once each feature is quantified by its impact, the resulting thermal efficiences can be reported and the reasons reported.
Is that a cut-and-paste you have there? From where?
My favorite quote:Just like those who hate on PF, or look down their noses at @53' Stude who cuts filters, or those of us who buy oils the board hasn’t seen & we pay for UOAs, some people will hate anybody who’s doing things outside of THEIR comfort zone. I’m not saying PFs tests are always based in science, nor am I saying all the UOAs get accurate interpretations, but some people actually DO things, while others just criticize.
We should applaud the doers, and ignore the idle criticizers. JMO…
It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.
Theodore Roosevelt
Unrelated but I like it so I'm posting it b/c I think Judge Smails would like PF testing.
"It's easy to grin, when your ship comes in, and you've got the stock market beat. But the man worthwhile, is the man who can smile, when his shorts are too tight in the seat." - Judge Smails
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