Better MPG with pure gas.

[Cujet]

Anyone seeing lower fuel economy in winter is probably due to other factors. These can be more idle time, thicker fluids, and possibly less complete evaporation while the engine is still cold.

My 2018 F150 2.7L EB is very sensitive to winter fuel. The instant winter fuel is put into the tank, MPG drops markedly. The engine is already warm, the truck is not cold starting and nothing else has changed. But MPG goes from 21 to 17 on my normal highway legs as soon as winter fuel goes in.

 

[CT Rob]

I lose 1.5-2 mpg with winter gas.

 

[Skippy722]

I accidentally filled the van up with E0 once... it got no noticeable change in fuel economy.

 

[hank2]

Some years ago, I used exclusively zero ethanol fuel for extended periods of time. That was in a 4.8 Silverado 4wd. On a daily 40 mile round trip commute I rarely broke 15 mpg with E10. With E0, I consistently got 16.5 mpg. At that time, the station I used priced E0 only $.10 a gal. more than the same octane E10. Today, all the stations selling E0 near me are more like $.50 a gal. higher. I currently only use E0 in my old '82 carbureted Dodge truck and my '81 carbureted bike. As well as all home power equipment. I've always thought I could feel increased low end torque on any vehicle with the E0.

 

[pghvolvo]

Just a heads up on tire pressure, there's been a lot of testing over the years and the difference between 40 psi and max sidewall 44 psi is barely noticeable. Many tests have shown between 40psi and say 44psi the real difference is around 1/4 to 1/2 mpg max. What is the cost $ to replacing suspension parts at 50-60K miles that got pounded from your rock hard tires? In every case there was a noticeable jump in fuel mileage between 35 psi to 40psi. My recommendation is to stay in the 38-40 psi range for the best fuel mileage.

I use to hang on a fuel mileage board with a bunch of tree huggers and those guys hated Ethanol in the gasoline. Depending on the vehicles tested with both straight gas and E10, everyone got better mileage with straight gas. With E10 it could have been as little as a 1-2% drop in mileage, to the other extreme where a few drivers got hammered with a 10-15% drop in mileage. As they say every engine and fuel system reacts differently to E10 over straight gas.

In my Volvo I use to get between 29.25 and 29.75 mpg on the highway using straight gas, with E10 the best I can do is 28.2 mpg. That's about a 4.5% drop in fuel mileage. That's much more than than the accepted 3.0% E10 drop expected in the perfect world scenario.

Obviously E10 cuts a vehicles fuel mileage and gasoline is taxed, more gasoline bought more tax revenue comes in. Due to the use of E10 and a jump in fuel costs over the years people changed their driving habits and vehicles today get much better fuel mileage compared to ten years ago. What did the states do because of the public's change, they increased the speeds on the highways up to 70 mph. OK so now you're really happy you can now drive at 70 mph but how much extra gas are you using per hour on the highway at 70mph vs say 65 mph in your vehicle? If you're interested you can do a Internet search on speed vs fuel economy.

I read somewhere a few years ago that the EPA tests all vehicles with straight gas. That might have changed because that article was is now at least five years old. If they have not changed the fuel over to E10 for testing, that might be why may vehicle owners find it almost impossible to meet EPA mileage estimates.

 

[hank2]

I read somewhere a few years ago that the EPA tests all vehicles with straight gas. That might have changed because that article was is now at least five years old. If they have not changed the fuel over to E10 for testing, that might be why may vehicle owners find it almost impossible to meet EPA mileage estimates.

Interesting point. I know that in the recent past all EPA mileage and emissions testing by manufacturers and the EPA was done using zero ethanol testing fuel. I didn't spend hours searching, but I did find an EPA proposal from 2011 mandating a switch to "tier 3 " testing fuel beginning in 2020.
Also a 2018 EPA fuel impacts document on results of Tier 3 test fuel. The Tier 3 test fuel has 3.46 % less energy by mass and 2.77% less energy by volume, compared to Tier 2. No mention of the word Ethanol, but the switch was mostly about oxygenated fuel.

Table 4.2.1: FTP Cycle: from this doc showed a Tier 3 to Tier 2 fuel mileage reduction across a diverse range of test vehicles from 1.83% to 3.10% .

https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100TLC7.pdf

 

[ammolab]

Originally Posted by whatnext
OK, basic info here:
If the manufacturer offers a 60,000 mile warranty on a specific tire and one vehicle that uses the tire requires 32 psi cold and another 44 psi cold, then if using your rationale, the vehicle with the lower factory recommended pressure would have significantly higher wear. I think that when discussing radial tires, the wear difference between max pressure allowed and recommended pressure would be negligible. The outer edge, center wear argument only being valid for extremely under inflated or over inflated values.

No, the difference in the recommended vehicles showing 32 vs 44 psi cold would be WEIGHT. The lighter vehicle would have a lighter weight and thus need a lower cold tire pressure. It is engineering and math...they don’t just randomly select a tire pressure.

 

[Jetronic]

ford explorer...

 

[loneryder]

10% ethanol should see about a 10% reduction in gas mileage and pure gas should see a 10% rise. I had a Dodge minivan that I drove all day every day in my sales job. It had a pretty accurate mileage indicator on it's trip computer. My son was in a private school a couple of hrs. from home and I would pick him up and take him back every weekend. I always got pure gas at a station on the way. It was the only pure gas I ever used. I started noticing my mileage going up and started watching it. It was a constant 10% increase in mileage when I used that gas. My driving conditions were the same every day/week. I even manually checked it. So to save our environment, we use 10% more fuel. It's not the environment, it's the Big Ag lobby.

 

[Danno]

Lone - Ethanol has 30% less BTU than pure gasoline. Math would say you should see about a 3% reduction in fuel economy. 30% of the 10% ethanol in the gas.
Unless the ethanol messed up your engine fuel management system to give you 10% worse fuel economy.

 

[kschachn]

I accidentally filled the van up with E0 once... it got no noticeable change in fuel economy.

Then as usual, there were other effects coming into play that negated the increase. Or the particular gasoline you purchased had a lower BTU value. Even at the same gas station the energy content of gasoline can vary up to 4%. This is well within the noise of being able to discriminate against environmental effects. No matter what though the lower BTU content of E10 is still there.

 

[Benzadmiral]

A large Exxon convenience store near me has a separate nozzle for E0 87 at ~.20 more per gallon. It's labeled as "Not An Exxon-Branded Fuel," so maybe the store has a different supplier. I've used it twice now and the Buick seems to be getting the same kind of mileage it got on E0 from the independent service station in the middle of the city. Their E0 87 ran about .08/gal. less than this place.

 

[y_p_w]

Lone - Ethanol has 30% less BTU than pure gasoline. Math would say you should see about a 3% reduction in fuel economy. 30% of the 10% ethanol in the gas.
Unless the ethanol messed up your engine fuel management system to give you 10% worse fuel economy.

However, the base gasoline (meeting the commodity standards) without ethanol can vary depending on the particular blend and even the particular crude oil source. I've heard it varies 4-5%. That itself could have more of an effect than just ethanol.

Besides that, 10% ethanol boosts the typical octane rating more than 2 numbers. Without some sort of oxygenate, there's going to be issues trying to meet the demand for fuel.

 

[Benzadmiral]

A large Exxon convenience store near me has a separate nozzle for E0 87 at ~.20 more per gallon. It's labeled as "Not An Exxon-Branded Fuel," so maybe the store has a different supplier. I've used it twice now and the Buick seems to be getting the same kind of mileage it got on E0 from the independent service station in the middle of the city. Their E0 87 ran about .08/gal. less than this place.

Been using this fuel and this station since mid-February, and my mileage is definitely up, 23.12 (calculated -- the instruments said 24.2) over the last 11 days instead of the usual 21-22. I did one more highway run to the suburbs than I usually do, and the weather has warmed a bit, so that might be part of it.

The amazing thing to me is that, though the fuel is labeled as non-Exxon, this station is selling it at 8 to 14 cents/gallon less than their 87 E10! I don't know if Exxon will give me the .06/gallon discount for using their card to buy this fuel, but even if they don't, I'm ahead of the game.

 

[GON]

I have a 2002 F350 V10 gasser of which I haul a gooseneck horse trailer. Fuel economy is brutal when towing with the V10. But it gets considerably worse when using an ethanol blend.

My experience is that a engine running ethanol blend under a heavy load requires noticeably more fuel per trip than running a non ethanol unleaded. When towing, I make an extra effort to find non ethanol blends.

 

[Benzadmiral]

Been using this fuel and this station since mid-February, and my mileage is definitely up, 23.12 (calculated -- the instruments said 24.2) over the last 11 days instead of the usual 21-22. I did one more highway run to the suburbs than I usually do, and the weather has warmed a bit, so that might be part of it.

The amazing thing to me is that, though the fuel is labeled as non-Exxon, this station is selling it at 8 to 14 cents/gallon less than their 87 E10! I don't know if Exxon will give me the .06/gallon discount for using their card to buy this fuel, but even if they don't, I'm ahead of the game.

I checked, and Exxon does give me the .06 off. 2.43/gallon instead of this station's 2.49 posted price . . . which today was .05 less than their E10 87.

Last Sunday when I gassed up, I did put 4 oz. of the Lucas Upper Cylinder Treatment into the gas. This is the $10 bottle I bought some months ago, and it has never improved my gas mileage to date, so I don't expect it's involved in the current mpg rise. When it's gone, I see no reason to buy another.

 

[sloinker]

No, the difference in the recommended vehicles showing 32 vs 44 psi cold would be WEIGHT. The lighter vehicle would have a lighter weight and thus need a lower cold tire pressure. It is engineering and math...they don’t just randomly select a tire pressure.

You are right. We were talking about tire wear versus inflation on modern radial tires. By inflating tires to their maximum rated cold pressure as listed on the sidewall, will it wear a tire out faster than the recommended pressure as displayed on the driver's door jamb placard? I say no. Now the ride/handling may be affected. Suspension and steering parts may suffer premature wear. The tires themselves would last as long as if they were at the lower psi levels. Would you save fuel? Probably a percent or so. Is it worth it? Maybe not. Low rolling resistance tires are stiff, new science is going toward non pneumatic solid tires. My engineering and math have rendered your opinion as most likely incorrect.

 

[y_p_w]

You are right. We were talking about tire wear versus inflation on modern radial tires. By inflating tires to their maximum rated cold pressure as listed on the sidewall, will it wear a tire out faster than the recommended pressure as displayed on the driver's door jamb placard? I say no. Now the ride/handling may be affected. Suspension and steering parts may suffer premature wear. The tires themselves would last as long as if they were at the lower psi levels. Would you save fuel? Probably a percent or so. Is it worth it? Maybe not. Low rolling resistance tires are stiff, new science is going toward non pneumatic solid tires. My engineering and math have rendered your opinion as most likely incorrect.

All the experience of tire companies and sellers says that excessive tire pressure results in more wear in the center because it's riding with a center bulge. There might also be worse handling because of less contact with the edge of the tread. But how much more that would be than the manufacturer's recommended pressure may depend on the tire.

 

[sloinker]

All the experience of tire companies and sellers says that excessive tire pressure results in more wear in the center because it's riding with a center bulge. There might also be worse handling because of less contact with the edge of the tread. But how much more that would be than the manufacturer's recommended pressure may depend on the tire.

When Nascar went from bias ply to radials a few decades ago there was a huge learning curve because the diameter change of the radial didn't respond like the bias ply when adjusting air pressures cold. The air pressure on the tire is adjusted to make effective spring rate changes on each corner, not diameter changes. After a tire is ran and heated, it grows and each tire is different in its growth and must be measured. The tire companies concern of over inflating for center wear and under inflating for edge wear were discussed up into the 1970's. not so much anymore. There is a range of pressure the tire will perform within. The manufacturer determines what it feels is the optimum pressure for the designated vehicle. I feel the lower the pressure, the higher the heating effect on the tire. The more heat, the less life. Take a look at the Firestone/Ford Exploder news of some years back. I rest my case.

 

[y_p_w]

When Nascar went from bias ply to radials a few decades ago there was a huge learning curve because the diameter change of the radial didn't respond like the bias ply when adjusting air pressures cold. The air pressure on the tire is adjusted to make effective spring rate changes on each corner, not diameter changes. After a tire is ran and heated, it grows and each tire is different in its growth and must be measured. The tire companies concern of over inflating for center wear and under inflating for edge wear were discussed up into the 1970's. not so much anymore. There is a range of pressure the tire will perform within. The manufacturer determines what it feels is the optimum pressure for the designated vehicle. I feel the lower the pressure, the higher the heating effect on the tire. The more heat, the less life. Take a look at the Firestone/Ford Exploder news of some years back. I rest my case.

They clearly set them low for ride comfort given the suspension.

I used to drive a 1989 Acura Integra. Lowest recommended tire pressure I've ever driven on at 26 PSI on all four. I did raise it to about 32, but not to the max on the tire.

Still - if my tire says max pressure on the sidewalk as 51 PSI, I'm not going to put it there since the ride is going to be horrible. I usually set it about 3 PSI higher than the manufacturer's recommendations.