An aquaintance of mine just bought on a month ago and i only have one question , why in gods name would you ever buy an E85 flex fuel engine let alone a 8-6-4 engine ?

  This is the second time around for GM with a 8-6-4 engine and the first time was a disaster to say the lest . The HT4100 used in Cadilacs in the 80s had this feature and i know of no engine including the Vega 2300 engine that GM had to replace in such high numbers. I dont know where you live but they dont sell E85 any where around here currently and if they did you would find that you get over 20 % LESS milage when burning it . If you have bought into the whole man made global warming BS thats your business but every study not connected to Big Agra has concluded that there are zero enviromental gains by burning ethanol by the time planting harvest and refining are taken into consideration .

 All the technology that has allowed us to biuld 800 HP small blocks can be applied to biuding 300 HP small blocks in your own garage that get  50 % more milage then your part time corn burner currently gets (thats better for the enviroment)

  My best advice to you is sell that dog quickly because you have been hood winked.

    On a positive note that yellow fuel cap your truck has is kind of cool..

You get less mileage with E85, but instead of paying $2.89 per gallon, you pay $2.25 as of today.  GM must be pretty happy with the flex fuel/displacement-on-demand engine as they placed a 5 year 100,000 mile powertrain warranty on them as they did with all their vehicles.  Also, Chrysler has had the displacement-on-demand in both the 340 HP hemi and the 425 HP hemi for three years now.   Apparently there is no maintenance problem with either the GM or the MOPAR D.O.D. engines as a GOOGLE search proved. 

"Cadilacs of the 80's", Cadillacs of the 80's?  JeesLouise, the 80's.  Think we may have come a long ways since then. 

Despite the claims by the ethonal lobby , in actual independent tests you get about 20 % less mileage on E85 and closer to 25 %  less under severe duty (towing) . Acording to http://e85prices.com/ the only site that up dates E85 prices every 24 hours nationally the average price difference is about 15 % so it costs about a 5 % to 10 % more depending on what your doing with your truck to run E85 .

   There are only about 1100 stations selling E85 in America compared to over 170,000 gas stations . Of those 1100 E85 stations 2/3 of them are in just two states , Illinois and Minnisota . California drivers have 257,318 flex-fuel vehicles but the state has only two public stations with E85. New Jersey has 116,512 flex-fuel vehicles and not a single service station with E85. There is not a single E85 station in over a 1/3 of America .

 I dont know where you live but I live in a very cold climate and starting an E85 vehicle is near impossible unless you have a block heater and plug it in like an old diesel . Since ethanol draws moisture in the fuel system is a constant problem in places with high humidity.For more on this read http://www.babcox.com/editorial/us/us020628.htm

All the vehicles with the worst reliability records have the longest warranty . Remember Yugos they had 5 yr 100.000  too and the cars with the best record have your basic 1 or 2 yr warranty like Honda , Toyota etc .

 Using E85 has no benefit for the enviroment and may be worst depending on what you read , Even the EPA and USDA have admited this begrudginly . The 2008 E85 engine is based on the 1955 Chevy so you can jeezelouise me all you want but what made the 80s Caddy a piece of junk applies to the new E85 engine .

I was going to edit my previous post but my question is why  would anyone with even a lick of common sence would buy a E85 vehicle ?

Are you an idiot or just plain ignorant.  Or are you another of the many "hate America" types.  You don't buy an E85 vehicle as you so stupidly put it, you buy a vehicle that just happens to be flexible in what gas you can put in it.  I've never put E85 in my 08 Suburban but if I wanted to I could. 

Like asking someone why anyone would buy a vehicle with heated seats, maybe because it comes with it standard.  Or why would anyone with even a lick of common sense buy a Suburban with rear heating/air conditioning.  It comes with it idiot. 

Why would anyone with a lick of common sense buy an E85 vehicle.  A lick of common sense.  What's a lick?  Sort of remember hearing it on the Beverly Hillbillies 40 years ago. 

Why would anyone with a lick of common sense buy a truck with a "tow mode button" for pulling trailers.  Who pulls trailers.  Oh that's right, ya get it as standard equipment on all freaking trucks built in this country.  Ya think?

speedyracer:

Why would anyone with a lick of common sense buy an E85 vehicle.  A lick of common sense.  What's a lick?  Sort of remember hearing it on the Beverly Hillbillies 40 years ago. 

Why would anyone with a lick of common sense buy a truck with a "tow mode button" for pulling trailers.  Who pulls trailers.  Oh that's right, ya get it as standard equipment on all freaking trucks built in this country.  Ya think?

 A "lick" when used as a noun means a "bit" or a "careless hasty effort" according to Merriam Webster but i am not surprised that you are ignorant of that since it seems to be a trend with you that also carries over into your lack of automotive knowledge 

  Your comparison of an E85 engine to tow mode is imbicillic since you have the choice of 3 other engines which are all better choices then the E85 engine. You made a foolish choice when you bought your E85 truck will you continue to make foolish posts to try to justify your foolish decision ?