Det intressanta rapport från Minnesota State University om Prius Gen I på E85 verkar ha försvunnit från sin vanliga plats så men jag hittar den nu här
http://beepdf.com/doc/28991/the_creed_p ... hanol.htmlCitat:
ABSTRACT
A 2003 Toyota Prius Hybrid-Electric vehicle was tested for operation on E-85 (85% ethanol/ 15% gasoline). Tests were done to determine if the vehicle could be operated safely on E-85 without any alterations.
The vehicle was monitored, while slowly increasing the percentage of ethanol, for conditions, which would indicate it would require system modification to adapt the car to operate efficiently and reliably on E-85. Tests were also conducted to compare operating on 89-pump gasoline against E-85. The fuel’s effects on emission levels, fuel economy, power output, and drivability were found
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RESULTS
While the results from the exhaust emission tests showed a decrease in all levels of emissions, the levels of Hydrocarbons (HC) and Nitrogen Oxides (NOx) were significantly reduced. The reason for only a small reduction in Carbon Monoxide emissions was primarily caused by a high count during the first phase of the L.A.4 FTP 78 trace. The first phase of this trace begins with a cold start. One of the differences between the properties of ethanol and gasoline that plays a crucial role; in cold starting and operating conditions, is their respective Reid Vapor Pressure.
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While using E-85, the check engine light came on. Upon inspection this produced a code indicating a lean condition was detected. During this testing, it was noted that the check engine light for the lean code would come on between 140-160 miles after clearing the code. The oxygen sensor output and the short- term fuel trim all indicated that the Air/Fuel ratio is stoichiometric, and that the fuel control module was maintaining the correct amount of fuel required. What is setting off the check engine light is that the system monitors the change in the base fuel map, which is indicated by the long-term fuel trim. If this change is outside of the set boundaries for an extended period of time, then a code is set to indicate that the fuel system is making greater adjustments to the fuel quantity to maintain the correct air/fuel mixture than is necessary under normal circumstances. The use of ethanol caused the fuel system to adapt the long-term fuel trim by an increase of 32.81%. ! This supports the lower average fuel economy of ethanol in the results. See figure 4. An added advantage of using E- 85 showed gains in power output, as shown on table 1. Although ethanol has a lower energy density than gasoline, due to its lower air/fuel ratio, and effectively cooling the intake charge, it allows more fuel to be introduced to the combustion chamber thereby providing the power gains seen.
Since E-85 tests were not done at ambient temperature of 25°F or less, it is not possible to comment on starting abilities in such conditions. While at 25°F the vehicle started without difficulty.
25°F ≈ -4°C
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Table 1: Maximum power and torque comparison
Gasoline 64bhp @4500rpm 80lb-ft @4200rpm
E-85 77bhp @4700rpm 106lb-ft @4250rpm
Det är 20% mera effekt och 32,5% mera vridmoment!
Några uppdates:
Winter, 2004
http://www.creedproject.org/Newsletters ... 7.No.1.pdfCitat:
The Prius has now been driven about 800 miles on E85. Compared to running on pump gasoline (i.e. E10),
we have noted two changes in the vehicle’s performance. First, fuel consumption has increased from about
45 mpg to 35 mpg for this time of year (late winter). This was expected since ethanol only contains about
3/4 of the Btu/gallon that gasoline contains. On a Btu basis therefore there was no noticable change.
Secondly, cold starting (<25°F) causes engine sensors to register a problem. However, allowing the engine
to idle for two to three minutes clears the problem. An engine code check indicated the problem as a “lean
fuel” mixture, again what we expected. This is consistent with the lowered vapor pressure of ethanol vs
gasoline at low temperatures. The vehicle is currently at MnCAR in Mankato undergoing final emissions
testing and analysis to determine whether cold starting performance will adversely affect the engine.
WINTER, 2008
http://www.creedproject.org/Newsletters ... 1.No.1.pdfCitat:
60,000 MILE PRIUS REPORT FROM CARLSON TOYOTA
These are the findings from the 60,000 mile service performed on Roger Aiken's Prius. I found that the engine was in extremely clean condition. I removed the valve cover to inspect the upper portion of the engine and I feel that it was cleaner than a normal gas operated engine. I also removed the injectors and inspected them and found that the deposits were less than a normal gas operated Prius. The Engine oil has always been noticeably cleaner when I change the oil. The same findings were on the spark plugs, they had hardly any deposits on them. I would have to say other than the smell (which I am not used to yet) the E85 operated Prius is cleaner than a gas operated one.
Michael Ahlers, Master Diagnostic Technician, Carlson Toyota.