Assessment of the Operation of Vehicles on Ethanol Blend Fuels

[johnydep]

Sorry if this has been reported before.

Assessment of the Operation of Vehicles in the Australian Fleet on Ethanol Blend Fuels

This is a must read; http://www.environment.gov.au/atmosp...els-report.pdf

Carburetor vehicls can not use Ethanol fuels, due to incompatable materials in the fuel system, and in some cases very poor performance.

Fuel injected vehicles produced after 1986 are fine, but the deposits left on valves, pistons & rings is a concern.

The photos tell the story, I'll be limiting my use of Ethanol fuel from now on.

7 CONCLUSIONS
The objectives of the study as laid out by the Department of the Environment and Heritage (now the Department of the Environment and Water Resources) in RFT 107/DEH2005 were to:

a. Obtain an assessment, based on an experimental study, of the suitability of vehicles in the current Australian fleet to operate on 5% and 10% ethanol blends (E5 and E10); and
b. Obtain accurate and reliable information which could be used to inform future polices relating to ethanol blend fuels, including labelling requirements.

Orbital developed a structured approach to achieve these objectives and have undertaken the necessary testing and analysis consistent with the proposed approach. The key findings from this study are summarised in Table 7.1. The findings are based on assessments of performance/driveability, materials compatibility and durability when vehicles are operated on ethanol blended fuels compared to operation on neat petrol. Three overall grades are assigned in this summary table:

• Unsatisfactory: The assessment of a vehicle highlighted evidence of negative impacts which could potentially lead to serious safety concerns and/or issues which would be clearly unacceptable to the average user.

• Doubtful: The assessment of a vehicle showed evidence of some level of degradation to the vehicle itself and/or its operability, but the concerns were not sufficient to warrant an unsatisfactory rating.

• Satisfactory: No issues sufficient to warrant concern were identified.

In assessing the results for performance/driveability the relative frequency and likely consequence of the issues was taken into consideration. For example, poor starting at -10oC would not alone cause the assigning of “doubtful” or “unsatisfactory” grading. For example, the Toyota Hilux was assigned an unsatisfactory grading due to its tendency to stall or hesitate on acceleration during the hot start tests, and not because of its tendency to occasionally stall on cold starts.
For materials compatibility, both the function of the fuel system component and the implications of a failure of that component were taken into consideration when assigning gradings. For example, with fuel injected vehicles the material compatibility of the fuel regulator diaphragm is critical as this predominantly elastomeric component separates fuel from the outside world. A leakage there would result in unmetered fuel entering the engine or leaking on to hot engine surfaces. With E10, all diaphragms showed signs of distortion (when wet) and stiffening (when dry). The Ford Festiva specimen additionally showed evidence of material breakdown (crumbling of the elastomer) and hence was assigned unsatisfactory rather than “doubtful”. Further the changes to the diaphragm material can also affect the performance of the regulator in terms of metering of the fuel system; however this is a secondary concern compared to potential fuel leakage and would not on its own warrant a grading of doubtful.

For durability results, the implications of a failure for any particular part of the engine or fuel system were taken into consideration when assessing the severity of the issues. Some issues, such as engine deposits, could go unnoticed until the vehicle breaks down, potentially requiring costly repairs. Should some other components fail, for example a fuel filter, the repair costs may be more modest but the sudden failure of the component while driving would represent a significant safety concern.
Reductions to the life of the engine/vehicle were also considered, but on their own would not be sufficient to warrant an unsatisfactory grading.
Carburettor vehicles tested on E5, regardless of age, had either unsatisfactory or doubtful aspects of materials compatibility and issues with their performance or driveability. The carburettor vehicles tested on E10 are not suitable for operation with that fuel.
All three vehicles had unsatisfactory materials compatibility with E10. The vehicles also had either unsatisfactory or doubtful performance or driveability. The carburettor vehicle which underwent durability testing was rated unsatisfactory on both E5 and E10.

The fuel injected vehicles tested are on the whole suitable for operation on E5, although potential durability problems were identified for one vehicle. Given that this is more of a long term issue it has been rated as a “doubtful aspect” rather than being “unsatisfactory” – though it is debatable if reducing an engine’s long term durability is acceptable.
The fuel injected vehicles tested on E10 had either unsatisfactory or “doubtful aspects” in terms of materials compatibility. More than half the fuel-injected vehicles tested also had “doubtful aspects” with regard to durability.
From the above summary of findings it is reasonable to conclude that ethanol blended fuels are not compatible with carburettor vehicles. The vast majority of vehicles built before 1986 are carburettor vehicles. It should be noted that carburettor vehicles also include some of the popular small cars built through to 1994, as well as some medium sized cars through to the late 1980’s and some 4wds and light commercial vehicles built through to 2003. The study results provide evidence against allowing E5 to be sold unlabelled in Australia since there are a significant number of vehicles on the road, effectively all carburettor vehicles, which are not compatible with E5.
The results from this study generally support advice from vehicle manufacturers and importers as published by the FCAI with regard to vehicles which are not listed as suitable for use with ethanol blends, particularly E10.
On the assumption that these results carry across to all vehicles which are not identified by the FCAI as suitable, an analysis of the Australian vehicle fleet’s ethanol suitability has been undertaken. This analysis was based on the current FCAI listing (as updated in December 2006) and the ABS 2005 and 2006 Motor Vehicle Census data.
Using the most recent Motor Vehicle Census, which provides data on the Australian fleet as at March 2006, it is estimated that at least5 59.5% of the petrol fleet would be suitable for use with E10 based on the FCAI advice. This compares with 55.6% of the fleet in March 2005. The increase in suitability in 2006 is a function of both the retirement of unsuitable vehicles (including pre-1986 models), and the entry of new, ethanol-ready vehicles into the fleet.
Based on the FCAI advice, a marginally higher proportion of the fleet, 60.6% using the 2006 ABS data, would be suitable for the use of E5 because some European models listed as not E10 suitable, are suitable for E5.