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kkreider13

Buying a 2006 Mazda Speed6

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Tomorrow I'm purchasing a 2006 Mazda Speed6 through a private sale (I would love to get the new Buick Regal Turbo but I really need AWD where I live).  I currently use E85 in my 06 F-150 FFV and love it.  So I've researched splash blending some E85 in the Mazda and I have a couple of questions.

 

First, for those of you who don't know much about the car it is a 2.3L turbo 4 cylinder that 93 octane gas is recommended.  From my research I've read people take premium fuel and splash blend with E85 to get about a 30% ethanol mix, sometimes more to get around a 95 octane fuel and most people say the car runs great off of it. 

 

Why should I pay for premium fuel and then splash blend with E85 to get higher octane?  Could I just buy 87 and splash blend 40-50% E85 to get to 95+ octane? What's the difference?

 

Is premium fuel E10?  Honestly I never buy the stuff so I've never even thought of it before. 

 

A lot of people who do mix with E85 in this car went the extra mile to change seals, fuel pump, fuel lines because the ethanol will supposedly eat through the rubber parts and install bigger injectors for better performance with the E85.  Is this really necessary?  One guy even went a far as to add an additive (snake oil, marvel mystery oil) to counteract the "damage" ethanol causes.  This is completely false right??  I caught a thread on here not too long ago saying we shouldn't need this additive when using any mix of ethanol in our gas.

 

Should I try to mix in as much e85 as I can until I get a CEL?  Whats the worst that could happen?

 

And lastly, what % of ethanol would I get the best mpg, or would is that just something I need to experiment with?

 

Thanks for you help on this!

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I cannot answer your concerns for this car directly- but I can tell you what I do in my 2004 Saab 2L turbo. It calls for 90 AON (average octane number) which is roughly the same as a 90 octane as marked on USA pumps (research+motor octane/2 or r+m/2). I have only put E0 premium in it twice and that was just on a long trip where I was testing mpg. It only drinks E20 (because it is easy for me) and is 91.5 octane where I get it. Some E20 would only be 89.5 octane due to it being make from suboctane 84. I have had it up to E30 but not beyond due to a guy I know who ran E30, E35, E40 for about a year and found that in his similar equipped engine (same engine - 1 year different) that he hit CEL's at about E38-E40. I chose to stay safe with mine cause this is my wifey's summer car and with a turbo I did not wish to hurt it. At E30 I got the same performance (actually applied more boost at times since no knock was detected) and the same mpg as E0 premium-- at least in my replicated interstate hwy trials (1100 mile runs). I did have 2 injectors stick BUT- this happened near the end of 2 back to back fills of E0 premium >:(. I never put premium in it again. So far I have put 65,000 miles on it with E20 or higher and have not had any more injector issues. She now has only 84,000 miles at this point.

 

A rough rule of thumb in low octane gas in lower % blends is that 10% ethanol will move a suboctane base gas up 3 octane to 87 and the next 10% about 2.5 points, and perhaps the 3rd 10% bump 2 octane more. This of course is referring to r+m/2. I do not like today's suboctane base gas and am avoiding it as long as I can due to it's poor motor octane number and poor mileage. Today's premium can be either an E10 or an E0. In a lot of areas 91 octane is E0 and 93 is E10 that way they only need to stock one grade of premium base gas-- but I have no clue what you have in PA.

 

You may be right on the need for AWD- my Saab is only a summer car , part due to boost spool torque drift, part due to it being about 4 inches off the ground (sport version), and part due to it being a manual (6 speed) gearbox. It just is not safe on ice and sitting so low- not a good snowplow either.

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As for the Marvel's...I use it roughly in every third tank and I have run E-20 or higher since day one on both my cars.

 

But the reason I use it is I know a guy who has had many high mileage engines and has always used. Has nothing to do with the fact that I use a little higher ethanol blend. No additive is required for higher ethanol percentages unless you rarely used the vehicle and let it sit. Then you mighy want to mix some STA-BIL in but that would be the same for straight gas too.

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Hi everyone.  New to the forum but not to cars, tuning, and e85.  I currently own a 2000 Buick Regal GS (Supercharged) and recently converted to e85 after great results from others in my community. 

 

OP:  Adding e85 to a forced induction car needs to be done carefully.  Under typical driving conditions there probably isn't a lot to worry about(if you're just blending) but when you get into boost your cars PCM is going to go want to bring on more fuel to deliver that power you want and to also combat knock retard which can occur with the higher combustion chamber temps that FI creates.  If you mix too much e85, despite it having a much higher octane than conventional gas you do run the risk of starving the motor of fuel and leaning out which over time or in extreme cases cause so much KR (knock retard) that the motor cannot compensate for this and cause internal damage to pistons from the heat generated by the lean condition.  Most MODERN cars on the road will generally tolerate a 20% ethanol blend with little to no effect on anything other than a mileage reduction and lower emmissions.  If you want to do it safely for a much higher percentage I reccomend getting ahold of a wideband O2 sensor or diagnostic scan gauge that can give you real time data regarding air fuel ratios and such.

 

In my personal case I needed to switch to larger injectors as well as a higher output fuel pump to compensate for the additional fuel quantity required by e85's lower btu/gallon output.  I went drastically larger than a normal conversion would dictate as I did it for the performance aspecsts of the alcohol in e85.  I took a motor making around 240hp and with the modifications done (headers, exhaust, custom tuning, overdrive pulley on supercharger,65#/hr injectors, ect...) it should be making north of 350hp.  When we adjusted the fueling tables to keep the car from going lean under boost we had to add nearly 34% MORE fuel to the tables and then slowly adjust things from there to dial it in. 

 

As far as a fuel additive is concerned I personally add a small amount of TCW-3 marine 2 cycle engine oil.  I mix it in at a ratio of 500:1 and have been doing this for a number of tanks of fuel.  If you read on the ls1tech forums and search for the term you will find MANY users of this with nothing but good results.  It initially started off as an additive for gasonline motors to promote better combustion of the fuel and to clean and lubricate the fuel system that ethonal blending aggravates. 

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