even thought the OEM stuff is very resilient and the fuel system is pretty "sealed up" for emissions purposes, as the tank gets empty there is a quite a bit of air in the tank along with the water it's carrying

the alchy will naturally try and absorb that water (it's a key ingredient in dry gas) and that water is now flowing through the fuel system

in OEM applications designed for E85 that doesn't cause too much problem in "normal use" scenarios and even in varying weather which is what the OEMs test for. I am not aware of any OEM "long term storage" tests with E85 but I believe they would bear out the simple facts that alchy drinks water like a thirsty camel.

alchy also evaporates quickly too and leaves a nasty little gummy residue and the alchy over long term can cause the normal gas to try and separate. The OEMs HAVE been battling these issues but it's not a problem for cars that are driven even sporatically and most flex fuel vehicles fill up pretty often.

I wouldn't recommend ANY fuel sitting for long time (6 months or more), but gas certainly has better longevity and better storage characteristics than E85

so if you want to store it long term, at least fill the tank up (as you should with gas too).

I'm not found of pulling injectors and fuel filters so I'll leave it up to you guys to be the "long term test pilots" for E85 storage.

I'm too busy driving the vette anyway to worry about it except in winter.

and I would also agree that many of the "e85 problems" are caused by improper rubber lines (need teflon lined or Stainless, wrong injectors, pumps, ect...) breaking down from E85 rather than water being absorbed.

so I'll leave you with a final thought, go sit on the couch and don't get up for 6 months, then jump up and run around. see what happens.

cars in general don't like to sit long term. its a machine and needs to be used. I used to run the ZR-1 club and all these low miler cars that sat with gas in them for 6 months or more failed to start (even with fresh fuel) fuel pump hangers rusted from moisture (tank not filled) and broke in HALF. fact not fiction. the pump hanger wasn't galvanized. that I hope helps illustrate the point

proceed at your own risk and good luck!

 

Tell ya what, Since you're basing your "recommendation" on an experience you had this one time in band camp with an injector clogging up; refute my fact with your facts. Band camp experience is not facts.

Bottom line, I presented proof from a manual that in a flex fuel vehicle, like a Tahoe there states nothing regarding storing a vehicle and fuel (e85 or not). It is now on you to prove my facts as wrong, other wise you're just wasting my internet.

 

Does the manual state anything about the tires if left for 5 years outside?

Did the manual state anything about all of those chevys they had to recall because they caught on fire? I mean it should right because the engineers this that blah blah blah.

You act like im the only one in this thread who is saying dont let it sit, that they have had clogged id1000, etc. So all of us with actual real world experience are wrong and some guy with a diesel truck who read something on the internet knows all.

 

You should get back on the short bus and drive back to the beginning of the conversation. This entire discussion was about a factory vehicle, which is a spin off on the probability that everything from tank to rails (note, I didn't say injectors, never had) should be perfectly fine because GM should have use parts that are e85 compatible simply because of economics (and the use of e10-e15 being standard in most states).

I dunno, does the manual? You tell me band camp leader.

 

And I'll say this again, yes they are compatible... But that does not mean that e85 will not go bad.

Keep talking about band camp, looks like someone had a trumpet shoved in his *** more than once.

 

But where's your proof they that the Tahoe is compatible?

 

My humblest apologies for starting this thread. I did not foresee so much of a heated debate. I am simply doing an ROI calculation.

I had the 599 eforce (let's not start another debate) kit installed in Pittsburgh. I installed Padt 1.75 headers (let's not start another debate). After the first tune, the highest rwhp on 93 octane at 12* timing was 535. The tuner told me the car was running 6-7 psi.

I contacted Edelbrock about what to do to increase boost pressure. The conversation resulted in purchasing a 3" pulley (opposed to the 3.5" which comes with the kit). Bigger injectors were highly suggested and I purchased id850's. For the second tune, the highest rwhp was 591 again with 93 octane and 12* timing. Boost was between 9-10 psi.

I told the tuner I was moving to Phoenix and he suggested that only 91 octane was available here so he reduced timing 2*. I did not have a dyno run made to see what was the resulting rwhp.

So, two questions. 1: How do I get the 2* timing back? There is a Sunoco station ten minutes away selling 100 octane unleaded albeit at $8.50/gallon. So a full tank of 18 gallons with 12 being 91 octane and 6 being 100 octane the quick math is an average of 94 octane. Current pricing would average ~$4.50/gallon. 2: How much rwhp is attained for each 1* advance in timing? Am I now at 491 rwhp instead of 591 or am I at 571 and, for me at least, I would not really care.

How much more e85 would be consumed than straight gasoline? 25%, 50%?
How much for a complete compatible fuel system?

I know e85 has a higher octane rating than 100 so timing could be advanced more than the 12* for which I looking but I would assume that would be the same with higher octane gasoline; it would just be less expensive.

I guess I should start with getting a tune with at least a 94 octane mix at 12* timing and see the results then see how much above 12* I can go. If I can go higher, what is the ROI on changing out the fuel system vs 100 octane gasoline? All this rests on the availability of 100 octane anyway. If/when that goes away, I would not hesitate in changing to e85.

 

I wise man once said "Never go full retard". You clearly missed that advice as well.

 

You would need to change the tune to get the timing back. There's no definite answer for how much hp 1* degree is. E85 might require 23-30% more fuel depending on your setup and target air fuel.

 

E85 is not over 100 octane in the units that are typically used in the US. It's more like 95-96. RON is closer to 102, MON is around 87, which averages (which is what we use at the pumps in the US) to an AKI of 95.

Running pure E85 will use about 30% more fuel

I'm sure you could add more timing without getting knock if you're at 12 now.. obviously someone with HP Tuners would have to do that. Ideally on a dyno so you can see before/after to be sure you're actually gaining (or not). No point in adding more if you don't gain anything (I'm sure you would pick up something.. just sayin')

I've also been told the flame travel speed of ethanol is faster than gasoline, so that alone might help. Whether it's true or not, I don't know.. I haven't done enough research on it to be sure either way.

 

i have zero experience with e force but if you're just looking for some more timing and more octane couldn't you just add an alky control methanol kit with a single M10 nozzle and get probably even more than 2* more timing plus probably cool the intake charge a bit as well?

 

Harden valve seats and guides??lol wut

 

E85 on a fi motor is the only way to go .

 

The original motor I specked out was never intended for E85 use and saw premature valve guide wear.

Every aspect of the motor in contact with fuel needs to be flex fuel compatible

http://www.jacksonautomachine.com/bu...-valve-guides/

 

After sitting for a bit over two months with ~e70 in the full tank. Non-climate controlled garage. Lowest temps maybe -10. Today its 40. Cold weather starting tune needs a little work, but after a few tries she runs fine.

 

Not bad