Long term impacts of E85 on a 5.3

[freakyt]

I have a Flex-fuel 5.3 in my Silverado, and I have run E85 in it before. There are plenty of fueling stations around southern Minnesota, so getting it is no problem here.

 

The only wierdness I've had so far is cold weather starting seems to take a little more cranking with E85. Once I get the enigne running, I notice no difference at all in the sound of my vehical or the performace when I floor it. The exhaust does have a really wierd smell when your running E85, it's kind of sweet smelling.

 

I'm going to have my truck for a long time, and I am wondering if it's better for the motor to run E85 or gas? E85 is a little cheaper right now, even though I get about 2 MPG less with it.

 

Any thoughts?

[chesney09]

I have a Flex-fuel 5.3 in my Silverado, and I have run E85 in it before.  There are plenty of fueling stations around southern Minnesota, so getting it is no problem here.

 

The only wierdness I've had so far is cold weather starting seems to take a little more cranking with E85.  Once I get the enigne running, I notice no difference at all in the sound of my vehical or the performace when I floor it.  The exhaust does have a really wierd smell when your running E85, it's kind of sweet smelling.

 

I'm going to have my truck for a long time, and I am wondering if it's better for the motor to run E85 or gas?  E85 is a little cheaper right now, even though I get about 2 MPG less with it. 

 

Any thoughts?

 

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I think they recommend using a bit more Gas with the E85 in the colder months to prevent that issue. If I recall it is in the manual.

[BlueTahoe]

Your observation of starting time is probably right on. Ethanol does have a harder time starting in cold weather. From what I have read the gas companies to be blending a 60%+- blend of ethanol for cold weather to aid in cold weather starting. Kindof like winter and summer blend gasoline. Might be that the gas company isn't backing off the ethanol content enough for the weather. As long as it starts good I wouldn't be too concerned about cranking time unless your seeing significant differences.

[freakyt]

Yea, I read that in the manual too, I'm not concerned about the cold weather starting. What I am concerned about is 100,000 miles down the road, will my engine be in better shape if I run E85 or unleaded?

[Ape0r]

Yea, I read that in the manual too, I'm not concerned about the cold weather starting.  What I am concerned about is 100,000 miles down the road, will my engine be in better shape if I run E85 or unleaded?

 

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The longer crank times are just because of the slightly lower energy content, as long as it'll start, no worries.

 

As far as wearing out faster.. well, your starter might wear very slightly faster due to the longer crank times, and as the engine presumably produces less HP on ethanol, it may have a larger tendency to downshift/unlock the TC, thus increasing RPM and wear. However, I would expect both of those factors to produce a negligable change over what would happen anyway.

 

Another argument is that because it produces less HP, the E85 may slightly reduce stress on engine components.

 

I think the bottom line is that the 5.3 will last for ******* ever as long as you change the oil once in a while =). The trans should go at least twice before your 5.3 is wore out on gas or on ethanol =).

 

I certainly wouldn't be worried about any extra wear if it were me, in fact, I've been looking into adding E85 capability to mine, but I think the cost/benefit ratio is a little skewed towards not doing so.. yet.

[BlueTahoe]

Ape0r is right on. Although I believe decreased horsepower can be debateable. It does take more fuel to produce the same energy but I have read many places where it does take more fuel but actually produces more HP when the A/F ratio is done properly.

 

I support E85 use and used it quite often in my Tahoe(just traded for a Trailblazer EXT) but I will try to give both the major pros and cons that I know of in your engine.

 

1. Ethanol will produce less carbon deposits. Not sure if this is due to ethanol being a better cleaner or because it just burns cleaner but it is widely accepted that E85 will reduce carbon buildup inside the engine. Thish could/should increase the life and performance of an engine. Not really any down side to this point that I have heard.

 

2. Take more fuel which produces less MPG. Some say this could cause cylinder wall washing which is a condition where fuel washes the oil off of the cylinder walls. The other part to this is some places will say that you will get more fuel dilution in your oil. This theory is true if you push too much fuel you can have these problems but I believe the 10%+- increase in fuel load in the 5.3 on E85 shouldn't cause this problem. If you were really concerned about this you could change oil more often and use a good synthetic oil.

 

3. Gas vs. ethanol lubrication properties. Some people are concerned with the valve train not being lubricated properly because gasoline has better lubrication properties than E85. In theory this is true and could be a concern in some High-RPM performance applications but since the introduction of unleaded fuel our valve trains should be built to perform just fine on E85 in most all normal vehicle applications.

 

These are the three major topics that I have heard discussed and am trying to present both sides of the topic for you to make an educated decision. Outside of these points the only other things I could think is in theory your fuel pump and injectors are moving more fuel so they could have a slightly shorter life. I hope this doesn't start an Ethanol debate. I did my best to supply both sides even though my opinion is it helps more than it hurts.

[freakyt]

BlueTahoe and Aper0r, you guys said exactly what I was looking for. I'm a fairly mechanical person, and I am very interested in this topic. Thanks for your views.

 

One thing you guys didn't metion is that E85 burns hotter, which could affect an engine in various ways depending on the climate.

 

Really, the only way to tell how E85 will affect my machine is to run it for 200k miles, or more

[BlueTahoe]

I'm suprised that E85 burns hotter. I have read articles about people using E85 in dirt stock cars and one of the perks they claimed was the engine runs cooler. May be the extra fuel provides more cooling to offset the increased burn temperature. I had read the another winter problem with E85 is if you run 85% ethanol other than starting hard it will take longer for the engine to heat up. I say if it doesn't cost more money to run then use it. I think the pros and cons are wash in the end so why not support the midwest instead of the middle east.