Flex Fuel?

[Mark Derail]

I was under the impression that E85 - the 85 was the Octane rating, not the Ethanol percentage.

Anyhow, up here in Canada, it is quite rare. Impossible to find in any cities, some odd places in the country might have. In 10+ years only seen two places, and they were independent owner/operators.
My last fill-up, I've noticed that they are now using winter gas, my mileage has gone down.
Will be worse with my winter tires.

The rest of your lengthy and well written post was informative but I think this part is just worded so it could be misread...

E85 is 85% alcohol, adjusted to 70% ethanol in the winter - balance gas.
Common gas mixes usually sold may have up to 10% alcohol, balance gas.
That's what you meant, right?

I do run a bottle of injector cleaner thru my gas tank on every oil change. Been thru that before. My have things have changed since I learned to drive on a double clutch '52 Ford.

 

[mrfixitchapman]

The rest of your lengthy and well written post was informative but I think this part is just worded so it could be misread...

E85 is 85% alcohol, adjusted to 70% ethanol in the winter - balance gas.
Common gas mixes usually sold may have up to 10% alcohol, balance gas.
That's what you meant, right?

I do run a bottle of injector cleaner thru my gas tank on every oil change. Been thru that before. My have things have changed since I learned to drive on a double clutch '52 Ford.

E85 is 15% unleaded gasoline and 85% ethanol. 'Gasohol' is 10% ethanol and 90% unleaded gasoline. Soon to be 15% ethanol and 85% unleaded gasoline. The exact opposite proportions to E85. Octane is a whole 'nother story. Octane rating is the fuel's resistance to spark knock, (pinging), and a high octane fuel burns more slowly than a lower octane fuel. Here's a tricky part, alcohol burns more slowly than gasoline under most conditions. Therefore an ethanol-blend fuel will exhibit a higher octane behavior. The blend burns more slowly in the combustion chamber, therefore acts like it has a higher octane rating. Here's another HOWEVER. However, the ethanol blend does not posses more energy. It burns more slowly. Another HOWEVER. However, since it burns more slowly the spark must initiate the combustion process earlier in the piston's upward travel on the compression stroke. Do not adjust your car, Flex-fuel vehicles take care of the fuel ratio and spark advance adjustments on the fly. For any percentage of alcohol and gasoline in the tank, (up to 85% ethanol), at any time.

If you look carefully at the label on the injector cleaner you will find the active ingredients are detergents and alcohol derivatives. You are, in fact, paying extra to do the same thing as the ethanol blend fuels do to clean your injectors and intake valves. Your money, spend it on whatever you like. IMHO you are better off changing the fuel filter more often.

Now, about cleaning the injectors and intake valves: Your Impala has Sequential Electronic Fuel Injection. The injector squirts a small amount of fuel into the area around the intake valve at the exact same time that the valve begins to open during the intake stroke. The cool part about this timing event is that the fuel isn't resting on the hot metal parts so the deposits tend not to build up as much or as quickly. We see engines in our shops with 150,000 miles and more that have blown head gaskets and worn-out timing chains but clean intake valves. SEFI improves fuel economy, engine longetivity and reduces emissions.

Winter and summer blends - fuel is blended for higher volatility in winter weather and lower volatility in summer weather. Octane rating stays about the same and additive packages are mostly the same. Winter blend fuels usually are lighter and have somewhat lower heat value per unit of mass. The lower heat value combined with more engine warm-up conspire to reduce winter fuel economy. This is worse as you go closer to the North Pole.

And, yes, I DO teach an entire unit on fuel blends in my Engine Performance Course. The course is seven weeks long at 25 hours per week. In case you were wondering.

DC

 

[DandyDon]

I was under the impression that E85 - the 85 was the Octane rating, not the Ethanol percentage.

Anyhow, up here in Canada, it is quite rare. Impossible to find in any cities, some odd places in the country might have. In 10+ years only seen two places, and they were independent owner/operators.
My last fill-up, I've noticed that they are now using winter gas, my mileage has gone down.
Will be worse with my winter tires.

Nope, not even close on Octane. MrFix gave a good explanation, but Wiki gives more info on Octane confusions with E85 at E85 - Wikipedia, the free encyclopedia

If you look carefully at the label on the injector cleaner you will find the active ingredients are detergents and alcohol derivatives. You are, in fact, paying extra to do the same thing as the ethanol blend fuels do to clean your injectors and intake valves. Your money, spend it on whatever you like. IMHO you are better off changing the fuel filter more often.

So I should not bother with my 2007 FlexFuel Impala, ya think...?

I know that cheap injector cleaner helped my old '95 F-150 a lot when the warning light came on. My daughter has a 2001 Impala, certainly not rated for FlexFuel, and I suggested some to her for her problems starting.

And I really do appreciate the expert advice.

 

[mrfixitchapman]

Nope, not even close on Octane. MrFix gave a good explanation, but Wiki gives more info on Octane confusions with E85 at E85 - Wikipedia, the free encyclopedia


So I should not bother with my 2007 FlexFuel Impala, ya think...?

I know that cheap injector cleaner helped my old '95 F-150 a lot when the warning light came on. My daughter has a 2001 Impala, certainly not rated for FlexFuel, and I suggested some to her for her problems starting.

And I really do appreciate the expert advice.

Thanks for the kind words, Don. The F150 had a very early version of port fuel injection. Those vehicles did, in fact, benefit from occasional fuel additives that could help keep the intake valves and intake ports clean. The SEFI system on the Impala is similar as far as hardware, but the operating strategies are very different. The
F150 also had a distributor where the Impala has a separate ignition coil for each cylinder. The Impala operating system has much more adjustment range for spark timing to go along with the much more advanced injection system. Just wait 'til you get gasoline direct injection. That's another gigantic leap forward. But that is a whole different discussion.

DC

 

[Mark Derail]

Direct fuel injection - at each cylinder. That Ford motor will be awesome, considering that over half of vehicles in Mexico/US/Canada are pickups.

I'm disappointed that it took Ford so long - like over 10+ years - to improve on fuel injection, better horsepower & MPG w/o making a motor smaller, bigger, or have more cylinders.
Imagine a Ford 4-cyl pickup with better MPG on the highway @ 65MPH with better MPG than a 2006 Prius.

Who cares if the cost is higher, the owner will get in back in fuel savings.

 

[D_B]

Some vehicles will have more HP when run on E85 .. my trucks rating goes up by 10HP to 325 ... but I'm more happy with the MPG of gasoline, 19/20 on the highway

Direct injection is better, and is already on some vehicles .. the new Camero has a standard 6 cyl engine, direct injected, 325HP that's rated 30MPG on the highway

 

[DandyDon]

...over half of vehicles in Mexico/US/Canada are pickups.

You travel much? We probably have more pickups vs cars than most countries, but not even in Texas is that true.

Ok, maybe you were closer than I'd thought. From Wiki....

According to the US Bureau of Transit Statistics for 2008 there are 255,917,664 registered passenger vehicles. Of these, 137,079,843 were classified as automobiles, while 101,234,849 were classified as "Other 2 axle, 4 tire vehicles," presumably SUVs and pick-up trucks. Yet another 6,790,882 were classified as vehicles with 2 axles and 6 tires and 2,215,856 were classified as "Truck, combination." There were approximately 7,752,926 motorcycles in the US in 2008.

A significant portion even tho not half.

 

[CuNanoTube]

Well, If the gas has 15% Ethanol (CH3CH2OH), which has an enthalpy of about -1400kJ/Mol (Negative because it loses potential energy when it burns, that turns into heat and in the case of engines pressure), and 85% octane (CH3CH2CH2CH2CH2CH2CH2CH3) which has an enthalpy of about -5000kJ/Mol, the amount of enthalpy per mol will be ~-4460kJ/Mol or 89% of the energy of pure octane.

Now, gasoline is not pure octane, so it may have less energy per Mole, but no matter what the hydrocarbon is alcohols will have less energy available as they are already partially oxidized.

Ethanol in fuel is a bad deal on an energy only (there are more factors present) comparison.

I should also note that if you include mass into the equation hydrogen wins by a large margin based on energy.

 

[D_B]

My main idea behind getting the flex fuel version in my truck ... I plan to have it a long time (last one was 20y/200k) and I thought it might be a good idea living in Ca to hedge my bet, not knowing what their fuel requirements might change to in the future

 

[NAM001]

i dont remember what the energy in fues is but ist is something like gas 100 btu diesel 150 btu prpopane 90 btu natural gas 80 btu. alcohol burns slower so it is a higher octane fuel with out the additive. it takes nothing to make 90+ octane fuel when it is ethonal . also i dontknow how it runs or starts in cold weather and at what temp the cold line is drawn at. so i wouldnt expect to see much of it in canada.