SN oil = improved mpg?
- Thread starter 209paulc
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The short answer is yes*.
*but unlikely to be measurable.
*but unlikely to be measurable.
Yeah, what Coprolite said.
Changing from 5w30 to 5W-20 should give a bigger mileage gain but even then, its extremely marginal, often immesaureable.
Changing from 5w30 to 5W-20 should give a bigger mileage gain but even then, its extremely marginal, often immesaureable.
Quite a difference between those two, you just might, but it will be very slight.
Originally Posted By: HWEaton
Not so long as they keep putting ethanol in fuel.
Gotta love a totally unrelated political hijack.
Not so long as they keep putting ethanol in fuel.
Gotta love a totally unrelated political hijack.
Ethanol reduces fuel economy by 3%. It produces less energy when burned, so your vehicle pulls more fuel to mix with the intake air. The result is richer running conditions, more deposits, worse fuel economy, premature failure of emissions system components, moisture build-up in fuel system and crankcase. ethanol's only benefit in the vehicle is to prevent fuel line freezing in winter. yes it helps provide a cash crop for farmers, but [censored] the farmers. I care more about my vehicles and their proper function.
SN/GF-5 oils are better equipped to deal with the byproducts of ethanol combustion in the crankcase and pcv system than SL oils.
SN/GF-5 oils are better equipped to deal with the byproducts of ethanol combustion in the crankcase and pcv system than SL oils.
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Originally Posted By: Jocephus
I'm still trying to figure out how a 10% Ethanol blend is supposed to save gas if every car I've run it in has less gas mileage.
The concept is this:
Say you get 20 mpg on pure gas and drive 12,000 miles/year. You will consume 600 gallons of product (which in this case is 100% gasoline) over that year.
Say you get 3% less on ethanol. That's 19.4 mpg, or round down to 19 mpg. For the same 12,000 miles/year, you will consume 632 gallons of product over a year. But since this product is only 90% gasoline, you have used 569 gallons of actual gasoline, vs. 600 gallons if using pure gasoline.
I'm neither for nor against ethanol, but that's the theoretical reasoning behind it.
I'm still trying to figure out how a 10% Ethanol blend is supposed to save gas if every car I've run it in has less gas mileage.
The concept is this:
Say you get 20 mpg on pure gas and drive 12,000 miles/year. You will consume 600 gallons of product (which in this case is 100% gasoline) over that year.
Say you get 3% less on ethanol. That's 19.4 mpg, or round down to 19 mpg. For the same 12,000 miles/year, you will consume 632 gallons of product over a year. But since this product is only 90% gasoline, you have used 569 gallons of actual gasoline, vs. 600 gallons if using pure gasoline.
I'm neither for nor against ethanol, but that's the theoretical reasoning behind it.
Quote:
Say you get 3% less on ethanol. That's 19.4 mpg, or round down to 19 mpg. For the same 12,000 miles/year, you will consume 632 gallons of product over a year. But since this product is only 90% gasoline, you have used 569 gallons of actual gasoline, vs. 600 gallons if using pure gasoline.
I'm neither for nor against ethanol, but that's the theoretical reasoning behind it.
But how many gallons of gasoline (or fossil fuel equivalent) were used to produce the 63 gallons of ethanol? According to all studies I have seen, more than 31.
The 3% fuel economy penalty looks high to me since the energy content of 1 gallon of gasoline = the energy content of 1.52 gallons of ethanol. But it may take more a gallon of gasoline to produce 1.52 gallons of ethanol. It depends on how you do the accounting. For a reasonably balanced account of the pro's and cons of ethanol as fuel, see
http://www.consumerreports.org/cro/2011/01/the-great-ethanol-debate/index.htm
Consumer Reports neglects to mention that recent studies concluding that ethanol production from corn is net energy-positive may be subject to confirmation bias because the government, who funds most energy research, looks favorably on studies that make ethanol look good. Government research funding is highly political.
Say you get 3% less on ethanol. That's 19.4 mpg, or round down to 19 mpg. For the same 12,000 miles/year, you will consume 632 gallons of product over a year. But since this product is only 90% gasoline, you have used 569 gallons of actual gasoline, vs. 600 gallons if using pure gasoline.
I'm neither for nor against ethanol, but that's the theoretical reasoning behind it.
But how many gallons of gasoline (or fossil fuel equivalent) were used to produce the 63 gallons of ethanol? According to all studies I have seen, more than 31.
The 3% fuel economy penalty looks high to me since the energy content of 1 gallon of gasoline = the energy content of 1.52 gallons of ethanol. But it may take more a gallon of gasoline to produce 1.52 gallons of ethanol. It depends on how you do the accounting. For a reasonably balanced account of the pro's and cons of ethanol as fuel, see
http://www.consumerreports.org/cro/2011/01/the-great-ethanol-debate/index.htm
Consumer Reports neglects to mention that recent studies concluding that ethanol production from corn is net energy-positive may be subject to confirmation bias because the government, who funds most energy research, looks favorably on studies that make ethanol look good. Government research funding is highly political.
Let's stick to the discussion of SN oil vs. SL, shall we?
Yes, there is improved fuel economy by switching to SN from SL, but it is nothing you will notice behind the wheel. The biggest advantage of SN is improved catalytic converter protection and E85 compatibility.
Yes, there is improved fuel economy by switching to SN from SL, but it is nothing you will notice behind the wheel. The biggest advantage of SN is improved catalytic converter protection and E85 compatibility.
SL oil is recommended for engines age built in 2004 or older. (http://www.pqiamerica.com/apiserviceclass.htm)
If you have some left over SL oil hanging around on the garage shelf, I wouldn't hesitate to use it as top-off oil or for the lawn mower. If the oil is older than 3 years, I'd say it has met its maker, and would recommend taking it to Walmart or your local auto store/garage for recycling.
For engines newer than 2004, stick with the manufacturer recommendation and use SN oil. It is simply a better oil that offers improved protection, and is able to cope much better with ethanol blended gasoline than previous specs. (Comparison between SN and SM, otherwise known as GF 5 and GF 4 http://www.gf-5.com/the_story/performance/)
If you have some left over SL oil hanging around on the garage shelf, I wouldn't hesitate to use it as top-off oil or for the lawn mower. If the oil is older than 3 years, I'd say it has met its maker, and would recommend taking it to Walmart or your local auto store/garage for recycling.
For engines newer than 2004, stick with the manufacturer recommendation and use SN oil. It is simply a better oil that offers improved protection, and is able to cope much better with ethanol blended gasoline than previous specs. (Comparison between SN and SM, otherwise known as GF 5 and GF 4 http://www.gf-5.com/the_story/performance/)
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Originally Posted By: 209paulc
Can I expect any improvement in fuel economy switching from SL rated GC to an SN rated synthetic (Castrol Edge w/Ti 5w30)? 2010 GMC 4.8L
Probably, though every situation is different. I went from Mobil 1 Extended Performance 5w30 to GC 0w30 and lost about 1/2 to 1 mpg in am '04 350Z. 3.5% loss.
Can I expect any improvement in fuel economy switching from SL rated GC to an SN rated synthetic (Castrol Edge w/Ti 5w30)? 2010 GMC 4.8L
Probably, though every situation is different. I went from Mobil 1 Extended Performance 5w30 to GC 0w30 and lost about 1/2 to 1 mpg in am '04 350Z. 3.5% loss.
To the OP:
I doubt you'll see a difference either way - really.
For anybody:
Pure ethanol has about 1/2 the energy of gasoline.
But 10% ethanol is NOT 10% less power.
Why? Because it is self oxygenating.
3-5% loss is about right.
For misinformed salv:
Ethanol fuels are NOT dirtier. They burn clean. And as to richness, there is an O2 sensor to keep things stable.
It does not reduce the life of emissions components.
I doubt you'll see a difference either way - really.
For anybody:
Pure ethanol has about 1/2 the energy of gasoline.
But 10% ethanol is NOT 10% less power.
Why? Because it is self oxygenating.
3-5% loss is about right.
For misinformed salv:
Ethanol fuels are NOT dirtier. They burn clean. And as to richness, there is an O2 sensor to keep things stable.
It does not reduce the life of emissions components.
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