So I have been using either Regular or Premium in the truck. I haven't noticed any significant improvements either way. If my memory serves me right, Regular is 85 octane and the Premium is 92. Well today I was daydreaming while filling and I ended up putting the 87 Octane Super with Ethanol. Is this going to cause me problems? I have heard negative things about the ethanol in what it can do to fuel lines, injectors and pumps/filters. I'm assuming doing it once won't be bad. Any input?

 

You will be perfectly fine with the 87 with Ethanol. We have nothing out here but gas with the 10% required Ethanol and I've never had any issues.

You have the 4.7L so I would run nothing but 87 (with Ethanol or no Ethanol). The compression isn't high enough on a stock 4.7l to take advantage of 91/92/93 octane.

 

Yea what he said...and one day if you run wicked mods like a couple of the guys on here you might wanna consider running premium.

 

I think I have to wait a little longer for any good wicked mods to be made to fit the '08 model year. Even my CAI doesn't fit properly because of some minor differences from '07 to '08.

But yes, one day!!

 

So I'm assuming that because there wasn't any posts that were very negative on the ethanol fuel, that it's ok to use then? I guess hearing bad things about it, I was leary... and I would love to know for sure before I continue to use it.

 

i have only used 87 unless i was using the superchips

 

So long as it is E10 (10% Ethanol) and not E85. If it is E85 you should only use it if you have the flex-fuel model and you'll still get lower mpg with it.

 

I have tried premium and now I use just regular cause I see no difference in economy between the two

 

Use both as well, no difference between the two for economy. sticking with Reg. as it's cheaper.

 

I've used e85 exclusively (except when in areas that I could not get it.) It is true that you get lousy mileage (seems like about 30% less), but (at least around here) the fuel is cheaper, so it usually doesn't cost much more to run it. I think your 08 v8 should be a flexfuel model (check for the flexfuel badge on the back of the tailgate and the yellow gas cap.) I was also told to not go from one fuel to the other with less than a 1/4 tank if possible.
As far as performance, it runs fine. The only time I had trouble was when it was -20 (farenheight) outside and it didn't want to start (of course my wife's PT cruiser running regular gas didn't want to start either!)