E85 for emissions test

Heskahoka

Supporting Member
Sep 10, 2012
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All things being equal, E85 does give you lower emissions in HC, NOx and CO2.
The above report is with a catalytic converter.

What are you trying to pass? A car with a catalytic converter or without? What are you worried about passing, HC, CO, CO2, NOx?

Running your car temporarily on E85, if it is not setup to do so, will cause it to go lean. This could be good for emissions but sometimes bad for HC and NOx.

As Turbo6inKY said, a proper tune with a cat should have no problem passing.
If you do try E85, it goes without saying, don't get into boost if you are lean.
 

Turbo6inKY

Short Guy
Jun 18, 2001
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But doesn't e85 have lower carbon emissions?
As measured at the tailpipe? No.

Overall, it's considered a renewable fuel, since the carbon in the ethanol comes from plants. The idea is you grow the plants, they suck CO2 out of the air as they grow, then you turn them into fuel and burn them. Net zero emissions over the lifecycle of the fuel (in theory, it doesn't really work out that way in practice).

But it takes x amount of energy to make the car idle and run. Producing x amount of energy in the engine is going to take y amount of carbon, regardless of whether the fuel is gasoline or ethanol.

The E85 is going to have fewer byproducts beyond CO2, CO, and NOx than gasoline, but they're generally not measuring for those at an emissions check.
 

Turbo6inKY

Short Guy
Jun 18, 2001
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The car is set up for e85 or 93 octane gas just have to switch chips. Using tt5.7 chips will reinstall Converter. Just wondering if e85 gives me a better chance at passing
I think that question has been more than answered with the information provided so far: no

The pieces required to pass emissions are a good tune and a functioning catalyst. The fuel is largely irrelevant.
 
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