03-23-2015, 10:02 AM | #67 | |
Colonel
197
Rep 2,802
Posts |
Quote:
|
|
Appreciate
0
|
03-23-2015, 10:22 AM | #68 | |
Captain
310
Rep 886
Posts |
Quote:
Ethanol doesn't "create" water in the tank. However, any water accumulation in the gasoline (far more likely from condensation in a marine environment, which is why you have better luck finding EtOH-free gas at a marina) can increase the water level to the point at which the two phases will split. With a 90% gasoline / 10% ethanol mixture at 60 degF, the split occurs when the water content reaches ~0.5% by volume. At 0 degF, the split occurs at a water content of ~0.3% (under 6 oz of water in a full 2-series tank). At that stage, the density of the ethanol/water phase is greater than that of the gasoline, and it drops to the bottom of the tank. Your fuel pump then pulls just ethanol/water into the engine. Unlike a layer of water at the bottom of your tank (which hits the engine and stops the combustion cycle, resulting in a nuisance), the ethanol/water mixture at the bottom of the tank will burn. In a riff on "Hey, Rocky, watch me pull a rabbit out of my hat!", your engine declares "Hey, 335boy, watch me stuff a reeeeeealy lean burn into my exhaust!" Something other than hilarity then ensues.
__________________
2015 M235xi coupe, Black Sapphire Metallic, Black Leather, Fineline Stream trim, Steptronic, xDrive, ZPP, ZTP, ZCW, ZDA, ZDB, 5DP, hk w/BimmerTech amp, Enhanced BT
Prior 40 years: 67 BelAir wagon / 68 LeMans Tempest / 70 Mustang Mach 1 / 72 El Dorado / 78 Corvette / 81 Subaru GL wagon 4WD / 83 s10 Blazer 4x4 / 85 Bronco 4x4 / 96 Bronco 4x4 / 04 Passat 4mo / 09 BMW 335xi |
|
Appreciate
0
|
03-23-2015, 11:29 AM | #70 | |
Captain
310
Rep 886
Posts |
Quote:
Fuel efficiency losses are real as well, across the board at 4% or so, higher in certain cars. It's an issue, but it's ubiquitous and doesn't get noticed as a result.
__________________
2015 M235xi coupe, Black Sapphire Metallic, Black Leather, Fineline Stream trim, Steptronic, xDrive, ZPP, ZTP, ZCW, ZDA, ZDB, 5DP, hk w/BimmerTech amp, Enhanced BT
Prior 40 years: 67 BelAir wagon / 68 LeMans Tempest / 70 Mustang Mach 1 / 72 El Dorado / 78 Corvette / 81 Subaru GL wagon 4WD / 83 s10 Blazer 4x4 / 85 Bronco 4x4 / 96 Bronco 4x4 / 04 Passat 4mo / 09 BMW 335xi |
|
Appreciate
0
|
03-23-2015, 11:37 AM | #71 |
Captain
312
Rep 862
Posts
Drives: '19 M2 '21 X5
Join Date: Mar 2014
Location: Calgary
|
Ethanol fuel increasing fuel usage is just a straight up fact. I don't need to do my own experiment to prove it. It is just science.
You car needs X energy/second to operate, that doesn't change. Pure gasoline has more energy per litre than gasoline with 10% ethanol. Therefore to operate at the same X energy per second as a car with pure gasoline the care with E10 will have to pump more gas into the engine per second to keep up. Now modern cars can do this just fine by tracking the amount of oxygen etc. in the exhaust and alter the mixture in real time faster than you can blink. ( that's what all those sensors are for!) So they don't actually apparently run differently as can be perceived. Flex Fuel vehicles do they same thing but on a much larger scale. But they do burn more gas per second by doing that. |
Appreciate
0
|
03-23-2015, 12:03 PM | #72 | ||
Brigadier General
659
Rep 3,320
Posts |
Quote:
|
||
Appreciate
0
|
03-23-2015, 12:27 PM | #73 | |
Colonel
197
Rep 2,802
Posts |
Quote:
Just read that mileage difference (assuming max 10% ethanol) is MAX 3 %. Again I don't care what anyone uses but so many around here are think 93 wil lmake the world of difference. This monthly thread is amusing. Last edited by 335BOY; 03-23-2015 at 12:38 PM.. |
|
Appreciate
0
|
03-23-2015, 01:00 PM | #75 | |
Brigadier General
659
Rep 3,320
Posts |
Quote:
you run 91 , ill run 93 well both be happy :-() |
|
Appreciate
0
|
03-23-2015, 01:24 PM | #76 |
Colonel
197
Rep 2,802
Posts |
Lurk? The car interests me. I just test drove one about 3 weeks ago ...possible next car. I think I have said more than once that I couldnt care any less what anyone uses. Sometimes the "Facts" here are a little off. Believe what you want and use what you want.
|
Appreciate
0
|
03-23-2015, 01:25 PM | #77 | |
Brigadier General
659
Rep 3,320
Posts |
Quote:
|
|
Appreciate
0
|
03-23-2015, 01:28 PM | #78 | ||
Captain
310
Rep 886
Posts |
Quote:
"Any BMW will run on 87 if you had to" Very true. The engine sensors would detect incipient knock, and would pull the timing back to prevent damage to the engine. It would certainly run, and without damage. "....would just make a few less HP. " No. A BMW running on 87 octane would make significantly less horsepower. Now, granted that the following is a 14 year old test, but it does address your point above: HP reduction due to octane reduction. You need to read the right section, specifically the results using octane below the engine manufacturer's specification for high compression engines with knock sensing: http://www.caranddriver.com/features/regular-or-premium "The results were more dramatic with the test cars that require premium fuel. The turbocharged Saab's sophisticated Trionic engine-control system dialed the power back 9.8 percent on regular gas, and performance dropped 10.1 percent at the track." A 30+ HP reduction would seem to qualify as more than "a few less" or "minimal and virtually imperceptible". The problem is that so many people watch a television program stating "There's no benefit to premium" without getting the caveat that the statement only applies to cars designed for regular. The assumption does not carry over to cars designed for premium. Quote:
http://www.fueleconomy.gov/feg/ethanol.shtml "Since ethanol contains about two-thirds as much energy as gasoline, vehicles will typically go 3% to 4% fewer miles per gallon on E10 and 4% to 5% fewer on E15 than on 100% gasoline."
__________________
2015 M235xi coupe, Black Sapphire Metallic, Black Leather, Fineline Stream trim, Steptronic, xDrive, ZPP, ZTP, ZCW, ZDA, ZDB, 5DP, hk w/BimmerTech amp, Enhanced BT
Prior 40 years: 67 BelAir wagon / 68 LeMans Tempest / 70 Mustang Mach 1 / 72 El Dorado / 78 Corvette / 81 Subaru GL wagon 4WD / 83 s10 Blazer 4x4 / 85 Bronco 4x4 / 96 Bronco 4x4 / 04 Passat 4mo / 09 BMW 335xi |
||
Appreciate
3
|
03-23-2015, 02:49 PM | #80 | |
Colonel
197
Rep 2,802
Posts |
Quote:
14 year old test? I looked up everything. I said 3%. What's your problem? You say 3-4. The point I trying to make is 10 ethanol is not evil and 93 isn't going to give you much if any more hp. I said the gain would be imperceptible. So busy trying to pick a fight that you didn't read everything? I'm just trying to get along here. What's wrong with that? |
|
Appreciate
0
|
03-23-2015, 03:04 PM | #81 | |
Captain
310
Rep 886
Posts |
No, you said "MAX 3", using caps to stress your point. A maximum of 3 doesn't even enter the 3 - 4 range.
Quote:
"Any BMW will run on 87 if you had to....would just make a few less HP. Its been proven many times that HP gain is minimal and virtually imperceptible. Probably about 10 hp MAXIMUM on untuned 235."That says nothing about 93 octane, and claims that 87 would make just a few less, not the 30+ HP reduction you would get with 87. Later on, you do mention that 93 gets you nothing in a Toyota designed for regular. That's fine, but it's also irrelevant. I did read everything, and as written, it's misleading. Getting along is fine, but dismissive quips following out-of-context quotes from TV news probably isn't the way to go.
__________________
2015 M235xi coupe, Black Sapphire Metallic, Black Leather, Fineline Stream trim, Steptronic, xDrive, ZPP, ZTP, ZCW, ZDA, ZDB, 5DP, hk w/BimmerTech amp, Enhanced BT
Prior 40 years: 67 BelAir wagon / 68 LeMans Tempest / 70 Mustang Mach 1 / 72 El Dorado / 78 Corvette / 81 Subaru GL wagon 4WD / 83 s10 Blazer 4x4 / 85 Bronco 4x4 / 96 Bronco 4x4 / 04 Passat 4mo / 09 BMW 335xi |
|
Appreciate
1
|
03-23-2015, 03:05 PM | #82 | |
First Lieutenant
150
Rep 395
Posts |
Quote:
My opinion is that the average driver who puts 87 in their 91+ "required" car likely won't feel a difference, because they aren't really looking for it, and isn't driving their car in a way where they would feel it anyways. If you are like me, going into high boost, and constantly comparing one drive feeling after another, listening for weird sounds and vibrations and are particularly in tune with your vehicle, it will be noticed. This feeling of less power on lower octane is exacerbated by higher intake temperature and whether or not you have a turbo car. I also had a 2015 STi for a couple months and my tuner was data logging the timing being pulled on one gas type vs another, while keeping intake temps consistent. The numbers don't lie and showed at WOT timing was pulled back and power was obviously lower on worse gas every single time. In some of the tune programming more than timing will be pulled such as boost. The only way to prove this one way or another is to throw an M235i on the dyno using 87, empty the system completely, run 93 through the system and retest with the same environment conditions. Do this several times and see what the difference is. Anyone want to volunteer? Last edited by configt; 03-23-2015 at 03:13 PM.. |
|
Appreciate
0
|
10-13-2017, 10:23 AM | #84 | |
New Member
9
Rep 12
Posts
Drives: 2015 M235i with M Perf Exhaust
Join Date: Sep 2017
Location: Kitchener, ON, Canada
|
94 Octane in Canada
Quote:
I had the Dinan Tune Stage 1 installed and their specs on horsepower and torque curves (based on dyno testing) all assume that 93 octane gasoline is being used. So, when I can find Ultra 94 easily, I will use that. Do I notice a difference vs. 91 octane. No, but I do not have access to a dyno to do any testing. BMW recommends Shell V-Power NiTRO+ Premium Gasoline for M cars since 2015. http://www.shell.us/motorist/shell-f...-gasoline.html with "unsurpassed protection against gunk and corrosion and superior protection against engine wear". I suspect this is just a marketing ploy by Shell and I don't have a "real M car" in any event. Besides, it is only 91 octane here. Is it 93 in the US? (But in Canada, the V gas contains no ethanol, which may or may not be a benefit - depending on which article you read.) Last edited by Peter K_B; 10-13-2017 at 10:32 AM.. Reason: clarified Sunoco, question re: Shell octane |
|
Appreciate
0
|
10-13-2017, 10:29 AM | #85 |
New Member
9
Rep 12
Posts
Drives: 2015 M235i with M Perf Exhaust
Join Date: Sep 2017
Location: Kitchener, ON, Canada
|
Shell V power is 93 octane?
I live in Canada and here, no Shell gas is higher than 91 Octane. Shell V-Power NiTRO+ See http://www.shell.ca/en_ca/motorists/shell-fuels/shell-vpower-nitro-plus-faqs.html
Shell has 93 octane in the US? Is it 93 in the V-Power NiTRO+? |
Appreciate
0
|
10-13-2017, 10:36 AM | #86 | |
New Member
9
Rep 12
Posts
Drives: 2015 M235i with M Perf Exhaust
Join Date: Sep 2017
Location: Kitchener, ON, Canada
|
Up to 10% ethanol is fine for BMW
Quote:
In Canada, only the Shell V-Power NiTRO+ is guaranteed to contain no ethanol. See http://www.shell.ca/en_ca/motorists/...plus-faqs.html I have not found any similar claim by Shell in the US. Last edited by Peter K_B; 10-13-2017 at 10:37 AM.. Reason: moved link to a more logical spot |
|
Appreciate
0
|
10-13-2017, 11:54 AM | #87 |
Colonel
3848
Rep 2,873
Posts |
Mild OT digression - I just did a cross country trek, and had not realized that in some states the ethanol vs. ethanol-free varies station-to-station, even amongst Top tier stations. If I had known ahead, I'd have tried to figure out who had eth-free versions as I was trying to max my mpg for a change (ECOPRO actually works well on the open road - hate it everywhere else I've tried it, but it got me at least +5%, 36.6mpg averaging over 70mph).
Here in NYS we can get eth-free, but max 91 octane, at least .40 more/gal, and locally it is only from a non-top-tier place, so I use 93 from Sunoco (no Shell locally). I think that ethanol is a mixed bag, not all bad - ethanol has some very useful properties, including that water absorption (we used to buy it in little bottles labeled 'fuel system drier' or pay hundreds for an injector system to add water/alcohol). I know it is an ecological and financial nightmare, but for cars designed to use it there are some positives. And all the talk about HP is a bit off base, w/o dyno results. It is torque that you feel, not HP, and probably where the benefits really come in - peak HP is pretty mechanically limited, but torque across the rpm curve is much more dependent upon dynamic settings that get adjusted down for poor octane or knock. I do believe that most enthusiasts can 'butt dyno' a 10ft/lb difference, especially at lower rpms coming off the line or at initial acceleration. |
Appreciate
0
|
Post Reply |
Bookmarks |
|
|