Yeah when I got gas on Monday I was surprised that it was up to $2.72. I don’t remember what it was a couple weeks ago but think it was somewhere around $2.40. I hear it is due to unplanned maintenance issues at the refineries, so the price should come down. Kinda makes it hard to swallow the proposed 20 cent tax hike in Minnesota plus sounds like the feds are trying for another up to 50 cents. I really don’t care to return to the $5 gas again.
As far as the gas mileage computers, whether or not it is as accurate as paper calculations I think doesn’t really matter. The important part is to spot any downward trends over time to signal problems that need to be addressed. Really though doing a paper calculation requires exactly determining how much gas was put in the tank to equal what was used. I’m not sure that is very accurate at all.
Sorry but that doesn’t even make sense. There is not going to be a difference accuracy of calculation is done based on E0 or E-10. The computer’s calculation is doing an estimation. It’s NOT metering the gas used. It’s monitoring things like injector pulses and RPMs to estimate gas usage.
Sure, it makes sense. Car computers are calibrated while efficiently burning 87 octane, 100% ethanol-free gasoline. Using (not burning efficiently) inaccurate, but “designated” 87 octane, 10% ethanol blends aren’t the calibration fuel for 87 octane, low-compression ratio gasoline engines.
No, they are not. They are “calibrated” with E10 since that is what the general population uses. Calibrated with whatever the fuel octane required by the manufacturer.
And Mike is right, the car counts injector pulses and other engine parameters and makes a calculation based on that. It is a volume calculation that doesn’t know if E0 or E10 is passing through the injector.
Car computers used in GASOLINE ENGINES are calibrated burning a version of E0 (gasoline), NOT with E10(ethanol blend fuel). Similarly, EPA accepts GASOLINE ENGINE MPG ratings from manufacturers burning a version of E0(gasoline), not E10(ethanol blend fuel). “ethanol in gasoline industry” advocates need to understand, the large majority of fuel engines are designed 87 octane, low-compression ratio GASOLINE engines, not high-compression ratio ETHANOL engines, which INDY cars use. Altho driven by grass-roots actions only, the number of E0 sources in Canada & the U.S. have risen from 2000 to 14,000+, while E85, fumbled by the EPA & the “ethanol in gasoline industry”, can’t establish 4000 E85 sources in the U.S. & Canada.
Do you know anything about computers? This is just nonsense you read on the internet. Each injector pulse injects a specific amount of gas into the cylinder. It’s calculated to with .0001oz. Then the ECU determines RPM and mileage to calculate mpg. There is no reason it needs to be calibrated for any type of gas or even diesel. Same system with same programming will work for any type of ICE system.
Complete poppycock. 11:1 is common in street cars and has been for 20 years. Ford’s 5.0 V8 truck engine has a 12:1 compression ratio. Mazda uses up to 14:1 in their SkyActive engines running on gasoline since 2011.
IndyCars are turbocharged 2.2 liter V6 engines with compression ratios of 11 to 12.5:1. As previously commented, this is lower than street cars, not higher.
It doesn’t need any calibration based on fuel type. It’s strictly a volume per mile calculation. The injector duty cycle is not fixed. If you put in a fuel with less energy per volume, the MPG will go down because it is burning more fuel to accomplish the same amount of work.
Well I’ve got something to add to this discussion. More of an observation than a statement. The last time I filled my 2005 Sierra 4wd with the 4.8 V8 engine, I used ethanol free 87 octane. I do not have a fuel economy readout option on the truck, so I always just calculate miles driven by gallons used. I generally get between 15-16 mpg. The 87 octane ethanol free delivered 15.2 mpg. Not too far out of the ordinary. Perhaps a little low, but chalked that up to different driving conditions, etc. The next tank, I switched back to E10 87 octane, which is what I normally use. I ran that tank down to 1/4 tank or so and filled up again. Calculating the mileage, I got 16.8 mpg on the 87 e10. I’ve had the truck about a year, and I’ve never gotten that good (good being a relative term here) mileage. So the e10 seems to have yielded better mileage, and the e10 yielded the best ever mileage following a tank of ethanol free. Kind of strange. My route didn’t change that much, and my driving habits are pretty similar. I’m not a speed demon, but I don’t try to drive expressly to conserve fuel either. The record fuel mileage is just an anomoly at this point. I am curious about it, though.
I’ve considered that maybe the last tank I got was the first tank this year that wasn’t “winter blend”. But I confess that I don’t know much about winter blend fuels and I don’t even know for certain if it’s necessary or used in moderate climate states like Mississippi.
At any rate, the mpg differences between my last two tanks were the opposite of what I would’ve expected. I really didn’t expect to be able to calculate any difference at all, but would’ve expected maybe .5 mpg’s better with the ethanol free, if that. I guess I’ll just have to see what the next tank yields and do a little more experimenting with ethanol free as well.
Back in the old days when I did the math calculation, one thing you had to consider was the outside temperature. If the temp is rising, the gas volume will expand and you get better mileage. There are just so many variables in the manual calculation that I rely on the electronic version more. Plus I can reset the thing on the highway to get an idea of the highway mileage.
Then back in the gas shortage days I used to teach the featherfoot driving course to maximize mpg. You got a card to keep track of mileage for every fill up. Regardless people always started getting better mileage after the course-just because they became more aware of driving patterns. After a while you just get burned out.
I just joined this site in an attempt to understand the whole E0 vs. E10 fuel economy talk going on. I own three vehicles and have a B.S. in Engineering S&M. I would like to think I’m very good in math, science and stats, but I’m not a gear head. I own a 2001 Toyota 4Runner (exceptional vehicle with 3.4L V6), a 2010 Volvo XC90 with the 4.4L V8 (Yamaha engine - for those that don’t know), and a 2018 Subaru Outback with the 3.6L flat 6. I’ve been very accurately tracking my mileage using both E0 (pure gasoline) and E10 fuel in all three vehicles and have seen very different figures than the 3-4% the Government is stating . So, I’m guessing all of this has more to do with your car/engine model than the fuel itself??? Am I wrong? My 01 4Runner is consistently getting 11-12% better fuel economy with E0, my Volvo is also consistently getting 12-13% better with E0, and even the newer 3.6L Outback is getting 10-11% better with E0. I’m using very simple math, but even the onboard mileage calculators on the Volvo and Subaru show similar differences (01 4Runner doesn’t have this feature). In order to maintain accuracy, for any of my calculations I only used figures when completely filling my tanks. I will say all three of these vehicles have extremely accurate fuel gauges, as I’m consistently putting the same amount of fuel in at each fill up ± 1/4 of a gallon - that is VERY accurate. So, can some experts please tell me what I’m missing?
About 20 for each vehicle. I will say some tanks are 87 Octane, some are 89 and some are 91. Remember Yahama makes marine engines and I’m guessing my V8 in the Volvo is a converted marine V8 engine. I already know marine gas engines don’t like ethanol at ALL. I love the horsepower and torque and it’s been trouble free. I just can’t believe the mileage difference - even on the onboard computer calculation. I’m amazed at the mileage differences in all three vehicles. Perhaps there’s a smaller 3-4% difference in smaller 4 cylinder engines vs. larger displacement engines like all three of mine. None are Turbo. The 4Runner is old being an 01, the Volvo probably is a converted V8 marine engine and the newer 3.6 flat on the Subaru is port fuel injection (not direct injection). I just took a very repeated trip in the Outback and got 27.5 mpg on E0 fuel. E10 fuel on this same trip results in about 24 mpg. So, I’m very confused at these huge differences.
Isolating the effect of changing one element on a single system will provide useful comparative data. When you also vary the systems, you see the effect the different systems have on the result. In other words, these 3 different platforms have different efficiency characteristics and are reacting differently to your control. Take three different wing designs; a 2x4 , a small prop plane and a glider wing. Increase air speed equally across all three. Do you get the same linear increase in system level performance for all 3?
Honestly, I would say 75-80% of the trips are exactly the same route and I mean every mile and every turn. Trips from my home to my parents house on the Chesapeake Bay - so, very level driving (no mountains and very few lights), trips to the Outer Banks of NC. I will also say 75-80% of my driving is on interstates and highways. I will also say I typically drive about 5-7 over the limit and am typically driving all three vehicles at 65-70 on interstates and highways. I know if I drive 50-55 I get much better fuel economy. So, 75-80% of my driving is at 65-70 mph. Perhaps this also plays into my large difference. I just don’t know, but I know how to do math
Gas mileage on ONE tank doesn’t mean much. You need multiple tanks and take the average. 11% increase using E0 is unusually high. Well out of the norm. But you should see a increase using E0.
10% (or now in some areas 15%) ethanol added to fuel is to add an oxygenate. This is to help reduce smog. Many areas like densely populated areas E10 is mandated by the Feds. It came out of the 1990 Clean Air Act.
MTBE was used for a while as an oxygenate. But that stuff is extremely nasty. It gets in the ground water and won’t leave. Ethanol is also very nasty, but it evaporates out of the water supply. We still have areas in NH where MTBE have poisoned peoples wells over 20 years ago. Some say it could take a couple generations before it’s down to safe levels.
Yes, but all three vehicles are positively seeing a 10% or greater increase in mpg using E0 fuel. Perhaps all three vehicles have similar fuel systems and onboard computers controlling things, but I seriously doubt it. Let’s see, my 01 4Runner was completely assembled in Japan, my 10 Volvo was completely assembled in Torslanda, Sweden and my Subaru was assembled in Lafayette, IN. All three have parts from all over the world. This really isn’t in my head and I’m not one to manipulate my testing by changing my driving habits either. I have a heavy foot and like to get where I’m going.
. So, I’m guessing all of this has more to do with your car/engine model than the fuel itself??? Am I wrong? My 01 4Runner is consistently getting 11-12% better fuel economy with E0, my Volvo is also consistently getting 12-13% better with E0, and even the newer 3.6L Outback is getting 10-11% better with E0. I’m using very simple math, but even the onboard mileage calculators on the Volvo and Subaru show similar differences (01 4Runner doesn’t have this feature). In order to maintain accuracy, for any of my calculations I only used figures when completely filling my tanks. I will say all three of these vehicles have extremely accurate fuel gauges, as I’m consistently putting the same amount of fuel in at each fill up ± 1/4 of a gallon - that is VERY accurate. So, can some experts please tell me what I’m missing?
, a small prop plane and a glider wing. Increase air speed equally across all three. Do you get the same linear increase in system level performance for all 3?