lane_change

I just recently converted my C6Z over to E85 with Carlos and the guys up at Quality Motorsports. I have been very pleased with the results so far compared to the "worries" that I had in regards to fuel mileage. I know that the dash gauge is not 100% accurate, but I am using it on both accounts in regards to my fuel consumption, mileage, avg. mpg, etc...

My results:

Trip to Dallas from Houston on 93 pump gas - 25.2 mpg average (fresh reset)
Trip to Houston from Dallas on E85 pump gas - 23.4 mpg average (fresh reset)

Daily driver uses, mix city/hwy/fun on 93 pump gas - 20.2 mpg
Daily driver uses, mix city/hwy/fun on E85 pump gas - 18.8 mpg

Cost of 93 pump gas currently - $2.79
Cost of E85 pump gas currently - $2.09

Overall, I have yet to experience a substantial decrease in fuel economy, especially when you factor in the price per gallon difference between the two.

Z.06

I really don't trust the DIC on gasoline vs gasoline, and am even more skeptical on gasoline versus E85, where there are more differences at play (ie density, energy per gallon), why not measure fuel mileage the old fashioned way before we claim victory? I guess we need a new volunteer since Lane Change has already converted.

lane_change

Yes, I do not trust the DIC completely either, I was just letting you know what my DIC stated before and after.

jeffreystar

What injectors did you go with?

PRE-Z06

depending on how it's tuned with the new injectors the calculated mpg may not be correct anymore

lane_change

The car is running 80lb injectors now for the E85. The car will be getting a nitrous setup once I do the heads, so we felt it would be better to have the injector capacity for the bottle.

AMGPilot

Could you calculate it manually and let us know if there is any difference? Thanks

jschindler

[disclaimer]I don't know if this is the same situation or not, just a thought[/disclaimer].

I put a "Power Commander" on one of my bikes. It basically changes the fuel/air ratio downstream of the ECU. After putting it on, my gas mileage on the bikes readout did not change, but the real gas mileage went down 10% because the ECU was still telling it to put out the same amount of fuel not knowing that another device downstream was changing things. The ECU is what sent the mpg data to the dash readout before the Power Commander did it's thing.

Again, may not be the same situation at all - but it is possible that something similar is going on.

Either way, thanks for the info!

lane_change

I can re-calculate my city/hwy/mix driving....just need to fill up and reset everything. I will post up my city driving after my next re-fill.

Katech_Zach

The DIC uses IPW to calculate fuel economy. When you change injectors the calculation is no longer accurate. When I switched injectors and to E85, my DIC showed about the same mileage as with E10 and stock injectors, but the actual economy dropped about 30%. You'll need to recalculate fuel economy the old-fashioned way for an accurate number.

DSteck

If you have injectors that flow more than 63.5 lb/hr in your car, the on-board fuel economy gauge becomes 100% useless, because it relies on accurate injector calibration data... which isn't possible because of the 63.5 lb/hr hard coded limit. If those are the Siemens Deka 80s, they actually flow damn near 90 lb/hr at 58psi fuel pressure... which is almost 50% higher than what you're allowed to enter into the injector flow rate table.

Take real measurements, and then tell us what you're getting. I bet you will be unpleasantly surprised.

lane_change

I just did the calculation from the fill up in Dallas to the fill up in Houston. The car drove 289 miles from station to station, so you are right. The car took approximately 16 gallons to fill back up.

289/16 = 18mpg at 80mph from Dallas to Houston.

So if the 25.4mpg was accurate on the way up, and the 30% is accurate for the additional fuel consumption of E85...25.4 x .70 = 17.78 which is pretty damn close to the 18mpg that I am calculating.

0Myhardtop

E85 gas consumption can be tuned for better MPG.

In the case of my ride, I am actually commanding a very lean idle and cruise AFR which helps with MPG and thus not a big drop from E10 to E85.

In the case of Lane-Change, many of the stock cruise settings were left unmolested until his set up changes. Honestly, he can run out of E85 and slap in E10 and be perfectly fine...it will a little too fat but it will only hurt a little of performance until the E85 is back in.

Thanks,
Carlos

rsmith1944

Can E85 clean up the emissions of a cammed motor to make it pass emissions testing in states that do sniffer testing?

Katech_Zach

It would be a step in the right direction. So theoretically yes.

0Myhardtop

Yes!!!

I passed emissions with my E85 Z and I dont even have cats

Thanks,
Carlos

clogan

The emissions inspectors here have recently started using mirrors to physically observe the presence of cats. If no cats can be seen, you FAIL, regardless of exhaust readings. (Also expose yourself to a substantial fine if caught w/o cats).
The world is a-changin'

CW

u1arunit

This is nothing new. They have been doing this for years here in PA. As with most anything in life it's who you know..

3 Z06ZR1

08jetvette

I got roughly 35 miles out of a half tank this weekend.