I took my 2004 Prius in for the recall (the electrical recall for stalling gas engines), a checkup, and an oil change. Shortly afterwards, I filled up my car at Sunoco, which adds up to 10% ethanol in their gas. Since then my car has felt noticeably less responsive, and my fuel consumption is higher than normal. I can't be 100% sure how much higher, because I'm not far into the tank yet, and initially I was doing more short haul trips which would eat gas. However, still it does seem higher. I do note that with other cars gasohol can make a difference with gas mileage. I don't know if that translates into decreased responsiveness too though. OTOH, I did fill up with Sunoco gas (10% Ethanol) for my 2001 Prius once, and I didn't notice much of a difference at all in either responsiveness or gas mileage. Anyone else notice the same sluggishness on the Prius 2004 (or later) with gasohol? How about with the recall fix?
Anytime I've used fuel with ethanol, my mileage has been lower. Supposedly, ethanol releases less energy than actual gasoline when it burns, which is good for octane, bad for power.
Do you actually notice the reduced power (like I am with my 2004) or is it just the gas mileage difference you're seeing? P.S. Impressive gas mileage you have there. I tend to jackrabbit, which means I may notice the power drop more than others, and my gas mileage is usually noticeably lower than yours. (Since you're in Anchorage I'm assuming yours are US gallon numbers, not Imperial.) Then again, most of my driving is city and short haul through stop-and-go traffic.
So I filled up again, this time with regular gas. Everything is back to normal again. The difference in responsiveness in the car is striking.
It wasn't the ethanol, since that actually *INCREASES* horsepower... which is part of the MPG penalty people observe. It is more likely the particular formula (other additives) in that particular brand of gas being the cause. Of course, it could also be that the ethanol simply cleaned out your system... so no matter what you filled back up with the engine would run better. Also note that LOW-SULFUR gas just became mandatory nationwide last week. So the odds of people witnessing a change in their gas are quite high.
I live on Long Island and the difference between NY and NJ gas is astounding. I am in NJ frequently visiting relatives. Anytime I fill up there I get MUCH better gas mileage. Case in point, filled up Sunday and drove home (48 miles) then drove R/T to Eastern Long Island. I now have 120 or so miles and the MFD reads 51.5. If I had filled up in NY, I can assure you my mileage would be low to mid 40's. It's THAT BAD!! What is the point of this exotic fuel mixture if I am burning more of it????? :blink: :blink:
Hmmm... Well, the most noticeable thing was that there was a lag in acceleration after a stop, and it seemed like it was that it took a little more to get the gasoline engine going after it had been shut off. It was more like my 2001 Prius, which definitely felt less responsive than my 2004. Possible I suppose. Unlikely, considering the reduced responsiveness was throughout the entire tank of Sunoco gasohol, and it disappearedimmediately after I filled up with Esso gasoline. I live in Canada.
Well, it turns out that all gas in 2007 must have at least 5% renewable fuel by January 1, 2007 in Ontario, and possibly 10% by 2011. I applaud the government's push to try to wean us off oil, but I'll admit it does have me worried, because my experience with my Prius is that the car just ain't built for gasohol. It really felt like there was something wrong with the engine or something when I was driving on gas with 10% blended ethanol. People use the argument that ethanol may increase the octane rating and thus the power, but this car isn't built to benefit from higher octane fuels, and like I said the reduction in power I felt was striking with 10% ethanol blended gas. I'm also a little skeptical of the environmental benefits of ethanol fuels, but I suppose this push is potentially more constructive than just maintaining the status quo.
being in an area where 10% ethanol is used year round, cant say what the difference would be. only one time have i not used it and it was at the start of a 450 mile trip all freeway and did not notice any real change in mileage. as far as responsiveness, always drive to get the best mileage so dont really know other than the car has never failed to get up and go when i needed it to. as far as gas mileage, ethanol has 10% less power than gas so a 10% ethanol mix will have about 1% less power. mileage should be reduced about a ½ mpg. i can live with that
<div class='quotetop'>QUOTE(DaveinOlyWA @ Sep 5 2006, 09:18 AM) [snapback]314576[/snapback]</div> I concur. I live in CA (land of the fruits and nuts), and we have 10% ethanol all year round, now that MTBE is banned. But I recently took a 2000+ mile trip that took me to other states where (I think) gas is gas, and I didn't notice any difference in power. While it's possible that I was getting slightly better mileage, the difference was too subtle to notice, given that my driving pattern on the trip was long haul cross country instead of in-town driving.
I still don't have my Prius yet, but I use 5-10% ethanol fuel all the time (Mohawk and Husky) - also in Canada. It keeps the engine internals much cleaner, including the throttle body (even though you wouldn't think fuel would get there - but it does through "standoff"). I didn't notice a change in mileage in any of four vehicles I've used it in, and I've always kept written records of fuel use and mileage. The change is usually too small to see, as it will be buried in the other larger variables. Of course those vehicle were all "gas guzzlers" compared to the Prius! Higher octane rated fuel doesn't have higher or lower energy, necessarilly. In the real world, it usually has slightly less, due to the additives having less. Ethanol fuel does vapourize better, so you'd think the engine would run better due to better mix in the combustion chambers. It also absorbs more heat, and that may be a negative in the Prius on/off engine. One of the potential downsides of ethanol fuel is the ethanol absorbs water. This is a -good thing- until the water starts to support certain bacteria that eat steel tanks! You may have gotten a bad tank from a station whose tanks were old and had started to rust. When that happens it isn't long before there is a breach, and lots of water gets into the tank. Comments based on draining a fuel tank, straining the fuel to remove the rust, and "panning out" the water - the litre of water in a 50 L tank! Then deassembling the fuel system to get all the water and rust out. Lots of fun. I'd suggest exploring further, with careful recordkeeping. Try a new station if possible, for the ethanol added fuel, to ensure you get good gas. BTW, if the gas station tanks are of the newer style, they will not suffer from the rusting problem. The ethanol then acts to dilute any water throughout the fuel, allowing the engine to burn it - preventing it from freezing and blocking fuel delivery in winter (gas line antifreeze built in).
<div class='quotetop'>QUOTE(djasonw @ Jan 10 2006, 10:10 AM) [snapback]186966[/snapback]</div> As an octane enhancer (allows using lower octane petroleum hydrocarbons), and for net reduction in air pollution from older cars.
<div class='quotetop'>QUOTE(richard schumacher @ Sep 6 2006, 09:07 AM) [snapback]315158[/snapback]</div> Please correct me if I'm wrong (someone always does), but I thought the original reason the US started requiring ethanol (and MTBE) was as an oxygenate. It caused fuel to burn more completely in older cars that tended to be the source of most pollution. It gave no reduction of emissions in modern cars with catalytic converters and oxygen sensors. The downside was that ethanol had a lower energy content than gasoline, so mileage was reduced by around 5% typically. Now we have a secondary reason to add ethanol, reduced petroleum dependency.
