Table of Economy using E10 and E85 blended in fuel tank

Notes:
Figures are from a 2000 model Mazda 323 4cyl 1600cc with EFI.
The driving conditions are a mixture of country, and surburban including highways and dirt or gravel.
Passangers varied from none to three.
Speed varied from 0 to 120km/hour.
$ value of fuel is based on the mix of fuel in the tank and the $ value of E10 (first row) is based on the latest prices.

Table of Economy using E10 and E85 blended in Fuel tank.

Fuel % Alcohol in Tank	Litres used per 100km	$ Value of fuel mix in tank per litre	Cost $ per 100km	Economy Diff % KM compared to E10	Economy Diff % $ compared to E10	Comments
10.00	9.14	1.67	15.25			E10 Average of 5 trips with highest and lowest kms disregarded
67.00	11.25	1.20	13.48	-23.14	11.57	adjusted the injection on this tank twice +13.5% then +27%
80.40	11.26	1.09	12.25	-23.19	19.70	went over the mountain and back on this tank
84.25	10.80	1.06	11.41	-18.26	25.16	Pumped up tyres to 36psi they were 30psi - drove from Nowra to Canberra  - Cruising -  Discount $10 off fuel price
43.07	8.98	1.38	12.37	1.75	18.86	added E10 drove back from ACT / NSW Border to Nowra – Cruising
57.18	9.34	1.27	11.85	-2.27	22.31	Suburban driving to and from work with one 160km run and one 80km run
74.38	11.24	1.13	12.74	-23.02	16.48	Suburban driving to and from work
81.91	9.74	1.07	10.46	-6.61	31.38	Suburban driving to and from work
82.75	9.77	1.07	10.43	-6.97	31.58	Highway Nowra to City 260km then suburban traffic
83.93	11.61	1.06	12.28	-27.02	19.45	Suburban driving to and from work
84.85	11.70	1.05	12.29	-28.01	19.38	Suburban driving to and from work
84.95	11.26	1.05	11.83	-23.26	22.42	Suburban driving to and from work
84.99	11.16	1.05	11.71	-22.10	23.18	Changed plugs were 1.8L plugs now correct 6mm longer and raised out of end changed oil to 5W30 castrol synthetic was 15W/60 penrite
85.00	10.68	1.05	11.22	-16.91	26.45	Suburban driving to and from work, some gravel roads

27 June 2008

This table shows the changes in economy that have occurred. The tank was filled with E85 three times at $1.05 per litre, taking Ethanol concentration to 84%, then because of location and no E85 pump within 200km, E10 at $163.7 p/L was added and the ethanol was diluted down to 43%. The litres used per 100km was the same at 43% as it was at 10%. The $ per 100Km was always better when extra ethanol was in the tank. Best so far was 23% improved on a tank of 84% ethanol.

I will continue to calculate and publish fuel economy and the changes in performance of the car.

07 July 2008

Interesting % difference $ compared to E10.

So far every blend of higher alcohol content has saved me money.

the last two figures for approx 82% ethanol saved 29%.

Savings since Flex Fuel conversion is $159.

Kilometers travelled 2804

Litres of fuel used 294.

17th July 2008

I noticed that the petrol station in town (Shell) was $1.663 per litre for ULP and $1.633 for E10. I put in 47.5 litres of  E85 at $1.05 per litre. It cost me $49.90 at the bowser and when it paid they gave me $10 off, I use the station rewards card ( $10 after every $200 spent ). If I had filled with ULP it would have cost me $79.30.
I have done the litres / 100km economy calculations again. 
The car ran at 19% improvement on cost per 100km compared to E10.

25th July 2008

Almost same figures as last tank of fuel

27th July 2008

Almost same figures as last tank of fuel.

Average for last 1000Km (Suburban Driving)

Km's Travelled	Litres Used	Fuel % Alcohol in Tank	Litres used per 100km	$ Value of fuel mix in tank per litre	Cost $ per 100km	Economy Diff % KM compared to E10	Economy Diff % $ compared to E10
997.9	110.7	84.58	11.52	1.05	12.14	-26.10	20.42

Suburban Driving is 20% Cheaper using E85

08 August 2008

Changed plugs and bought fuel filter not done yet.... in tank job, dont really want to open tank, but it is one of recomended changes one conversion has done 1000kms. Economy may have improved with new oil and plugs.

Car is a 2000 model Mazda 323 astina
It has a 1.6L 4cyl engine. I use the car to drive from Nowra to Sydney on the weekends and to work in sydney traffic on the week days.

I have been filling up with fuel in Sydney and Nowra, the average concentration of ethanol in my tank has been 66%.

Kilometers travelled	Litres used	Fuel % Alcohol in Tank	Litres used per 100km	$ Value of fuel mix in tank per litre	Cost $ per 100km
8391.80	868.59	65.97	10.29	1.17	12.03

this is $ 1016 worth of fuel to travel 8391 km.

If I was using E10  I estimate the cost would have been $767 for the fuel
based on $1.60 per litre and an economy of  9.14 litres per 100km