What octane gas do you use? (The Mother thread)
03-18-12, 10:48 PM
#196
I've been reading many of these ethanol threads on other forums. At 15%, I suspect we'll see far more fuel related issues. For older cars, you already have a good idea what is going to happen. Same concerns I have for the '80 Celica. The Lexus may be ok though long term I'm having the same thoughts...not good.
03-19-12, 01:13 AM
#197
I'm in Missouri, and all gas has at least 10% ethenol, which is NOT good for my 25 year old Porche and a real concern. So....
How is ethenol working out for Lexus? I've been buying premium at a Casey's stations and getting about 22mpg. We just got this car on the road 2 weeks ago.
Will the contnued use of 10% cause an issue? Some companies are using ethenol as a cheap road to higher Octane (which makes sense since the ethenol burns slower than gasoline), Will this be a problem for my 94 LS400 with ~200k?
I've heard rumers that MO will be - or aleady has - mandating at least 15% Ethenol.....what will that bring?
How is ethenol working out for Lexus? I've been buying premium at a Casey's stations and getting about 22mpg. We just got this car on the road 2 weeks ago.
Will the contnued use of 10% cause an issue? Some companies are using ethenol as a cheap road to higher Octane (which makes sense since the ethenol burns slower than gasoline), Will this be a problem for my 94 LS400 with ~200k?
I've heard rumers that MO will be - or aleady has - mandating at least 15% Ethenol.....what will that bring?
15% in all honesty MAY be fine, but you would need to worry about etoh corrosion and possibly water condensation.
most gas out here in cali is 10% ethanol as well.
03-19-12, 10:38 AM
#198
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10-15% of ethanol in the fuel won't do any damage, it'll just make your mileage worse. Also, it won't bring up the octane rating -- 91 octane with 15% ethanol is still 91 octane.
Ethanol is lighter than gasoline, so you need to flow/burn more of it to get the same amount of energy per unit. So, having more of it in the fuel will result in worse MPG.
Stan
Ethanol is lighter than gasoline, so you need to flow/burn more of it to get the same amount of energy per unit. So, having more of it in the fuel will result in worse MPG.
Stan
03-19-12, 11:57 AM
#199
10-15% of ethanol in the fuel won't do any damage, it'll just make your mileage worse. Also, it won't bring up the octane rating -- 91 octane with 15% ethanol is still 91 octane.
Ethanol is lighter than gasoline, so you need to flow/burn more of it to get the same amount of energy per unit. So, having more of it in the fuel will result in worse MPG.
Stan
Ethanol is lighter than gasoline, so you need to flow/burn more of it to get the same amount of energy per unit. So, having more of it in the fuel will result in worse MPG.
Stan
03-19-12, 12:11 PM
#200
One interesting aspect is the tree huggers/environmentalists and EPA. They worry about carbon and trying to balance some of the pollution regarding fuel efficiency makes me...
I find the GPS MPG amusing because it calculates the carbon footprint for fuel used. 
I find the GPS MPG amusing because it calculates the carbon footprint for fuel used.
03-19-12, 12:35 PM
#201
that's not to say ethanol is bad, under the right circumstances (like in Brazil, where unsubsidized it's extremely cheap due to a natural abundance of raw material from their sugar industry) it can be both economical and environmentally friendly.
corn-based ethanol is not a clean fuel, but it does make excellent tuning fuel, with E85 coming in right around 95-100 octane. (R+M/2)
03-19-12, 12:53 PM
#202
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Ethanol in US is a joke, don't even get me started on this. I was all into it a couple of years ago when they promised stations to be everywhere -- I was planning to run my Subaru on E85 for more power -- but that never happened. **** ethanol.
Stan
03-20-12, 09:44 PM
#204
Hi, guys forum lurker for the past few years. Finally decided to sign up since I own a 99 ls400 now..
I recently drove from Illinois to NC and got 26mpg running midgrade driving 10 over the posted speed limit most of the time.
In the past few years since gas prices have been going up I've decided to run midgrade on my higher compression engine vehicles that require premium. The ones that didnt ping and got the same gas mileage I kept running midgrade.
The secret to pumping gas is go the the stations that have the most business. Fresh gas is the key. Have you ever pumped 93 and felt sluggish because of bad gas? Its happened dozens of times for me.
I've even asked friends that worked and owned gas stations. The octane rating for the gasoline is shipped at a higher rating. After it gets into the tank in the ground is when it dilutes.
So really mid grade may end up 90-91 octane if its always fresh since everyone doesnt pump 93 octane.
93 may end up the 94 maybe 95.
The only real way to find out forsure is buy testing equipment.
I recently drove from Illinois to NC and got 26mpg running midgrade driving 10 over the posted speed limit most of the time.
In the past few years since gas prices have been going up I've decided to run midgrade on my higher compression engine vehicles that require premium. The ones that didnt ping and got the same gas mileage I kept running midgrade.
The secret to pumping gas is go the the stations that have the most business. Fresh gas is the key. Have you ever pumped 93 and felt sluggish because of bad gas? Its happened dozens of times for me.
I've even asked friends that worked and owned gas stations. The octane rating for the gasoline is shipped at a higher rating. After it gets into the tank in the ground is when it dilutes.
So really mid grade may end up 90-91 octane if its always fresh since everyone doesnt pump 93 octane.
93 may end up the 94 maybe 95.
The only real way to find out forsure is buy testing equipment.
05-06-12, 09:32 AM
#207
E85 okay?
Previous comments have pretty well described the ecological benefits of ethanol, but using food corn to create it is a pure stunt of political idiocy. So, I won't get into that issue.
However, the discussion of octane is intertesting. Octane does not effect mileage by itself; it DOES allow other adjustments to be made to the engine which CAN effect mileage. Higher octane fuel allows the engine to have higher compression without pre-ignition (pinging), and it might allow slightly advanced timing. Higher compression results in a greater fuel density in the combustion chamber at TDC, so at ignition, the flame front more thoroughly burns the fuel before the piston travels too far down the bore. This results in more power, from the same amount of fuel= higher mileage. Ethanol has lower energy/gallon than gasoline. ANY ethanol in your fuel gives you lower energy per gallon, which will cost you mileage. PLUS, there are very few rubber compounds that do well with both gasoline AND ethanol. Flex-fuel cars are built using those compounds, others are not. The government decided that 15% ethanol probably wouldn't cause rubber seals, etc. to degrade in less than five years, so by then nobody would blame ethanol for fuel problems. But with E85, you will have them much sooner.
However, the discussion of octane is intertesting. Octane does not effect mileage by itself; it DOES allow other adjustments to be made to the engine which CAN effect mileage. Higher octane fuel allows the engine to have higher compression without pre-ignition (pinging), and it might allow slightly advanced timing. Higher compression results in a greater fuel density in the combustion chamber at TDC, so at ignition, the flame front more thoroughly burns the fuel before the piston travels too far down the bore. This results in more power, from the same amount of fuel= higher mileage. Ethanol has lower energy/gallon than gasoline. ANY ethanol in your fuel gives you lower energy per gallon, which will cost you mileage. PLUS, there are very few rubber compounds that do well with both gasoline AND ethanol. Flex-fuel cars are built using those compounds, others are not. The government decided that 15% ethanol probably wouldn't cause rubber seals, etc. to degrade in less than five years, so by then nobody would blame ethanol for fuel problems. But with E85, you will have them much sooner.
