I have been blending E85 (85% Ethanol) in my 2003 TL for YEARS and it runs great. I currently have over 147k and it still runs like a champ on E30. Don't worry, you do not need to change fuel injectors to run E20 or E30.

My car loves the higher octane that E85 has (105 octane). I blend it with
E10 to get E30 that has a 92 octane rating.

Don't be afraid of adding a 2 - 3 gallons of E85 on every fill up.

Start out with 1 gallon only since it will take the varnish off that gasoline has left behind.

2 x 85 = 170 (2 gallons of E85)
8 x 10 = 80 (8 gallons of E10)

170 + 80 = 250

250/10 = 25% Ethanol.
-------------------------
2 x 105 = 210

8 x 89 = 712 (89 octane rating of mid-grade)

210 + 712 = 922

914/10 = 92.2 Octane Rating

Compare "super" (not regular) to the cost of E85 and you will see that by blending you will reducing your fuel costs and raise the octane rating.

 

It's only safe to run 10% ethanol (by mass, I believe) without making changes to your ECU/fuel lines/etc.

 

Also I don't think your math is right. I'll check it tomorrow in my fuel blend spreadsheet. You need to do things on a mass basis not volume so you'll need the density of gasoline (which tends to vary a lot by season) plus the fact that gas stations already add up to 10% ethanol but not always the full 10% and your calculations are a guestimation at best.

 

The math may be fuzzy but it works. The TL can take up to 33% Ethanol using that formula. I did figure that the gas I use is E10 or 10% ethanol. This forumla works. If I go over the 33% I will get a check engine light to come on. So I bring the concetration below 33% (using the fuzzy math) and reset the code and all is well.

Since there are only like 18 gallons of gas in a barrell of oil. So by using a higer concentration of Ethanol we reduce our (USA) dependance on foreign oil. Brazil did and we can too.