10 % ethanol

[buckw13]

what do you think of 10% ethanol in gas used in a tow vehicle. I have a gmc sierra with the 5.3l v8 and was wondering if i would lose too much power in the vehicle by running this. It is about 10 cents cheaper a gallon and i was just wondering if the savings is worth it. Thanks

 

[ondarvr]

Re: 10 % ethanol

While on a dyno, or in other lab testing you may see a power loss, in the real world you will most likely never know if you're using it or not.

We've had blended fuels where I live for a very long time and nobody loses any sleep over it.

 

[fire831]

Re: 10 % ethanol

Almost all gas has 10% ethanol in it. You must be talking about E-85 with 15% gas in the ethanol.

 

[109jb]

Re: 10 % ethanol

You really won't see any difference in a modern fuel injected vehicle. Reason is that the injection system can compensate and you just burn a little more fuel if it has ethanol in it. Worse fuel economy, but no real world power loss.

 

[IVAZ]

Re: 10 % ethanol

If anything, you should see a slight increase in power and a slight decrease in fuel economy. They don?t build alcohol race cars to go slower.

 

[keepNitreel]

Re: 10 % ethanol

Hate 10% ethanol, it burns faster but not much of a choice where I live.

 

[willieboy]

Re: 10 % ethanol

No, but they do build them with 13:1 compression to be able to utilize the higher detonation, etc... of Ethanol. In a non-race vehicle, Ethanol will result in a slight fuel economy and power loss. Most people will not really notice the difference when running E-10 (normal urban gasoline). Know, E-85, you notice the difference big time.

 

[IVAZ]

Re: 10 % ethanol

Edit

 

[109jb]

Re: 10 % ethanol

If anything, you should see a slight increase in power and a slight decrease in fuel economy. They don?t build alcohol race cars to go slower.

Ethanol has a higher octane rating and is therefore more resistant to detonation that gasoline, but you don't get an increase in power without an increase in the compression ratio to take advantage of the higher octane. Alcohol race cars use very high compression and/or supercharging to achieve very high power output. Top alcohol race classes use methanol or ethanol, but Top Fuel which is what you usually see on TV uses nitromethane. Nitromethane is a whole different animal from ethanol or methanol.

In any case, the ethanol blended fuels at the gas pump don't have an overall higher octane rating so you can't raise compression and therefore can't get more power. You wouldn't do that anyway. Mainly you just lose fuel economy because a gallon of ethanol has less energy content than a gallon of pure gasoline. If I remeber right a gallon of pure ethanol has about 85% the energy content that a gallon of gas does. If you do a little math you get that a 10% ethanol blended fuel will have 98.5% the energy content that pure gasoline does. So, you lose about 1.5% fuel economy.

 

[jrou111]

Re: 10 % ethanol

You probably won't notice a difference.

BTW, E in gas makes the engine more resistant to predetonation. A modern ecu equipped with a knock sensor will detect this and advance timing more = slightly more power.

E85 requires much larger injectors and the fuel mapping is way different. If you're not running a vehicle equipped to run E85 from the factor OR running an aftermarket tunable ECU then you should stay away from it.

 

[Silvertip]

Re: 10 % ethanol

When an engine tends to detonate or ping, timing is retarded to compensate, not advanced. Because of the higher octane of the E85 the engine can take advantage of that so the ECU can advance the timing. I have 40,000 miles on a Chevy Impala 3.5 Flex Fuel and as long as E85 is 35 to 40 cents cheaper than regular gasoline I use it as it is either a break even or a plus as far as cost goes. It is a real bargain when there is a 60+ cents difference as there often is when gas prices creep up. Typical highway mileage is 30 - 31 on regular and 27 - 27.5 on E85. Here is an Edmunds test on a Flex Fuel Tahoe.
Take it for what it's worth. E85 was not made available to increase fuel mileage or to save money (although it can do that). It is just an alternate fuel source. South American countries (Brazil to name one) run their cars on ethanol.

http://www.edmunds.com/advice/alternativefuels/articles/120863/article.html

 

[IVAZ]

Re: 10 % ethanol

Ethanol has a higher octane rating and is therefore more resistant to detonation that gasoline, but you don't get an increase in power without an increase in the compression ratio to take advantage of the higher octane. Alcohol race cars use very high compression and/or supercharging to achieve very high power output. Top alcohol race classes use methanol or ethanol, but Top Fuel which is what you usually see on TV uses nitromethane. Nitromethane is a whole different animal from ethanol or methanol.

In any case, the ethanol blended fuels at the gas pump don't have an overall higher octane rating so you can't raise compression and therefore can't get more power. You wouldn't do that anyway. Mainly you just lose fuel economy because a gallon of ethanol has less energy content than a gallon of pure gasoline. If I remeber right a gallon of pure ethanol has about 85% the energy content that a gallon of gas does. If you do a little math you get that a 10% ethanol blended fuel will have 98.5% the energy content that pure gasoline does. So, you lose about 1.5% fuel economy.

Its very unlikely that you would see a power increase. That's why I said "if anything".
Nitromethane is not alcohol, its added to it to increase its "burn" ability. The race cars in my area are that are the most popular are the old VW beatles. They dont run any forced induction at all. These cars do have ridiculous compression ratios. They are definitely a lot faster than their normal counterparts ( they run 9's and low 10's in the 1/4 mile).
At the current time my father is building a 502 that will be a "booze burner". Its going in a 1968 Chevelle that's a pure track car.
You are correct about alcohol having less energy than pure gas. It does not necessarily mean that alcohol will be slower than gas though.
My wife's truck can run on either ethanol or normal blend gas. Its never been run at the track but, the seat of the pants feel says it runs quicker on pure ethanol.

 

[kenmyfam]

Re: 10 % ethanol

You may have used it already without knowing it. Not a lot of noticeable difference.

 

[109jb]

Re: 10 % ethanol

Nitromethane is not alcohol. Correct. I only mentioned it because other readers may have thought the "race cars" you were referring to were the top fuel dragsters and funny cars they see on TV.

As for the fuel economy, here is a link done by the American Coalition for Ethanol that showed about 1.5% lower fuel economy when using E10. So, the fuel economy is very little difference.

As for power. Yes modern vehicles can advance a bit due to increased tolerance to detonation due to higher octane rating which may yield a touch more power, but I seriously doubt that it would show except on a dyno.

 

[H20Rat]

Re: 10 % ethanol

**deleted**

 

[boomer2]

Re: 10 % ethanol

I have a turbocharged car that I burn e85 in. With my custom tune, I get substantially BETTER torque and power, with the same mileage. E85 has an insane octane rating, 105-115, so you can add alot more timing and boost than you could ever get away with on pump gas.

Same here. V6 turbo. I run a mix of about 60/40 ethanol and 93 and back that up with methanol injection that is progressive with the boost. I can safely run pretty high boost (mid twenties) without beating the bearings out of it or cooking a piston or popping headgaskets. Now if only the crank can stand up....... I use the 60/40 mix for a bit of added safety to keep from running out of injector as the ethanol doesn't have the energy per pound that gasoline does.

 

[109jb]

Re: 10 % ethanol

Guys. The original question WAS NOT about E85, but about E10. The E10 that you get these days does not have a high octane rating.

 

[getusummm]

Re: 10 % ethanol

Its a good thing the original poster was asking about tow vehicles and not his boat. E-10 is ok, but only in later model flex fuel vehicles that are designed to handle it. Carb and standard fuel injection vehicles will lose a little mileage but not enough to really notice. Now switch that to E-85 and look out. However, the E-10 will clean the heck out of your entire fuel system. If you have an older vehicle, be prepared to change lots of filters and pumps.

 

[Silvertip]

Re: 10 % ethanol

Not true at all. You DO NOT need a flex fuel vehicle to burn E10. That is pure rubbish. Flex Fuel vehicles ARE required to burn E85. E10 has been used in our area since 1997 long before the term Flex Fuel and the E85 requirements evolved.

 

[kenmyfam]

Re: 10 % ethanol

Not true at all. You DO NOT need a flex fuel vehicle to burn E10. That is pure rubbish. Flex Fuel vehicles ARE required to burn E85. E10 has been used in our area since 1997 long before the term Flex Fuel and the E85 requirements evolved.

Absolutely correct.
Flex Fuel = E 85