Best fuel? Fuel recommendations?

[kram1984]

Ive got around 6000 miles on my FFH now. I started out not really paying much attention where i was getting fuel and always got unleaded. Mileage was fluctuating from around 35 avg from tank to 42 or so per tank. Then I got a tank that had some 26mpg trips in there (!) and around 30 for the tank.... So I went to strictly shell unleaded. I've been alternating sometimes shell unleaded, sometimes unleaded plus from the same shell station (havent kept exact records from every single tank), but from my commute ~20 miles to/from work I was always getting around 40/44 (40 there and then 44 the way back) The last tank or so from shell with unleaded has been 36/40 for the trips, and when I went to fill up this week they have a sticker now on the pump saying "Contains Ethanol". I havent tried premium unleaded yet as I'd heard higher octanes don't add power and only help if the engine is made for the higher octanes.

 

What are other people's experiences? same mpg for unleaded/unleaded plus? Anyone "Tried" the higher octane unleaded premium? Best results with a certain company? E10 gasoline or ethanol containing labeled gasoline running your mpg 10% less?

 

If E10 runs at 10% lower mpg, then it seems the E10 mixture is less than worthless... As if I could still get gas without the ethanol it'd only take 9/10 the amount (which is the same amount of gas Contained in the E10) to match the performance of the E10.

[wstcoaster07]

I buy shell and shell only simply because it is considered one of the "top tier" gasoline's. I started this with my Jeep about 2 years ago after a lot of research online about the quality of gas for the life of the engine, along with the fact that my mpg on my jeep went up 2mpg on average by using shell only.

 

ALSO, you should pick up a Shell Platinum credit card (assuming they still offer it) because it gives you 5% off all shell gas. As long as you don't keep a balance on it and get stuck with interest, it is a great deal.

[kram1984]

wstcoaster,

 

Have they started adding ethanol at your shell, and have you tried multiple grades or just unleaded? what do you get in mpg for a roundtrip drive of > 10 miles? (I say roundtrip because it seems like that would balance out downhill/uphill/etc)

[jeff_h]

Mileage was fluctuating from around 35 avg from tank to 42 or so per tank. Then I got a tank that had some 26mpg trips in there (!) and around 30 for the tank....

 

You didn't note where you are from -- the brand of gas could be a factor, but from many miles of driving a hybrid I've found that the cold weather causes an MPG hit since the ICE runs much longer to get heated up, and more often to stay heated up. Also, really hot weather will cause an MPG hit too and the HEV drains quicker from running the AC and needs the ICE to charge things back up.

 

I have 11,000 on my FFH now and until 1,000 miles (10 days) ago I had gotten my long term MPG up to 42.2 and even was at 42.3 for a day... then we got a hot day of over 90 and the AC worked a bit extra while I saty in traffic. Then for the past several days it's been under 50F in the morning and the ICE runs more when first getting going. So now I have sunk to 41.5 and as it gets colder I will probably sink back to the high 30s for the long term MPG and wait for Spring to get back over 40 (will probably take until Summer if it's doable).

[rfruth]

hey kram (or anyone) did the higher octane help or couldn't you tell ? The E10 should account for at most a 2 MPG decrease. The rest is happenstance. (or thats what I found with my last vehicle)

[kram1984]

jeffh, I'm in San Antonio, TX. My long-term mpg is around 36 and slowly creeping up. The 26 trips/bad tank of gas was not during cold were were at 95 to 105+ heat we had for a long time this summer, and I did have the air blasting and I do have remote start. It's the stupid Sirius TravelLink's fault... I wanted to test out the gas prices "feature", which seems pretty worthless except maybe on roadtrips and looks to have actual cost me $$$. I was attributing it to the heat first... but then I switched over to going to that one shell exclusively and saw an immediate improvement. Since then the sun seems to have gotten tired of blasting us with 100+ days and it's on a short vacation, and I've been getting a consistent 44/40 during communte for several tanks including around 40 on 2x~200 mile 70mph highway trips.

The manual says anything with more than 10% ethanol will damage the engine so that got me concerned of the stations here all switching to ethanol mixes. I also do not know if the individual stations or companies mix the ethanol and therefore some may "accidentally" get wrong ethanol %'s. (I've heard they mix in some of the detergents/additives themselves and can get those wrong).

 

rfruth, wish I'd kept a real detailed history I've mostly just looked at it each trip not written down. It hasnt lowered it I think I've seen at least 2-4 mpg better with the midgrade but that's just an estimate from memory. If it's 2 then it's not worth it but if I get 4, that's 10% and the cost is less than 10% more so it'd make sense then. I've never tried higher octane than the midgrade.

[wstcoaster07]

The gas at our local shell I believe has no ethanol in it yet (or they just haven't posted the sticker clearly)... I say yet because I have noticed it start popping up in cities around ours.

 

As for octane, from my limited research a while back (while also looking up top tier gas) I believe the consensus was that the octane level did not correlate to better gas mileage.

[junehhan]

I highly recommend you use the octane recommended for the vehicle by the factory. If the engine isn't calibrated or designed to run on higher octane fuel, running a higher octane than necessary would be a waste of money. Higher octane fuels from my understanding burn more slowly, and could actually hurt performance.

 

I believe the key is running a good quailty brand from a station that you trust. I exclusively run Shell or BP depending on which is available when I need it.

 

Running an ethanol blend is going to hurt performance, but you may not be able to avoid it in certain regions of the country.

[rfruth]

I agree more octane than is called for (regular for the FFH) is a waste, there are those that believe a higher octane than is called for is good cause the different additives help clean your fuel system etc... - as for ethanol blend hurting performance, I ask why for F-1 cars run E-100 ? (mpg hit yes)

[SGM Dean]

In my experience, I gotta blame poor milage on the weather when all other factors are equal. Wind, rain, and puddles this past week or so has pulled my average down about 3 mpg.

[swsaint]

At one time (and maybe it still is) gasoline came in by pipeline to a central distribution point, and you will see a number of brand and unbranded distributors located around those pipeline points. The gasoline was all the same and it was additive packages (such as BP Ice guard-does that still exist?) that was added as the gasoline was loaded into the tanker truck on the final leg to the gas station. Each brand has their own additive package which might include a coloring agent. So the gasoline was all coming from the same pipeline, unless you were lucky (or unlucky) enough to live close to a refinery and you were getting it directly from the source. A former neighbor of mine worked as a distribution manager for a very major oil company and told me about this. Surprised the heck out of me, but when you stop and think about it, it makes sense. Now don't know how they handle the octane issue or how the ethanol thing works, but for sure the 6 or so grades at Sunoco were all based on blending the low and high octane gas at the pump based on the blended you dialed in.

[junehhan]

I agree more octane than is called for (regular for the FFH) is a waste, there are those that believe a higher octane than is called for is good cause the different additives help clean your fuel system etc... - as for ethanol blend hurting performance, I ask why for F-1 cars run E-100 ? (mpg hit yes)

 

Ethanol doesn't hurt performance as it's naturally higher octane is very good for vehicles designed to run on it. I had the opportunity to ride along in a brand new Corvette Z06 that recently had an E85 conversion done to the motor and calibrations(major motor work). I have never been in anything that fast in my life before. However, I think people meant to say that you take a significant fuel economy hit with ethanol blended fuel.

 

As for the poster who mentioned Sunoco fuel, you actually have to be very careful as their Ulra 94 octane stuff is utter crap. It uses a special additive that is blended in at the pump to achieve that 94 octane rating. Many people in the automotive world have talked about it being utter garbage in it's knock resistence as some tuners have found it to be even worse than standard Shell/BP 93 octane fuel.

[Oman]

Ethanol has less energy per gallon than gasoline has, but it has a much higher octane rating. Ethanol has around 23.5 MJ/litre or 85,500 BTU/US Gal of energy while gasoline has about 32 MJ/litre or 125,000 BTU/US Gal. Ethanol has an R octane of about 129 while pure gasoline is around R 87 or so. Ethanol also uses a different oxygen / fuel ratio for proper deflagration (burn as opposed to detonation). Essentially engines are designed to work on a specific air/fuel mix and a specific spark timing to create the most efficient burn. The computer and combustion sensors can adapt a bit up or down with the timing and mixture based on the current fuel burn characteristics using an array of sensors that monitor the combustion event and resulting gases.

 

Your best bet is a quality station supplying the recommended fuel for the vehicle. Most fuels come from the same pipeline and storage containers but as stated just get different additives. The additives do make a difference - usually in the long run as skimping on detergents has been a long-running cheap fuel issue and that's why there are regulations on it. An often overlooked area though is the delivery system. A good trucking and delivery system (station) will have good clean in-line filters and perform water contamination mitigation. If they let the tank get low and don't have good filters then all sorts of gunk can get pumped into your cars tank.

 

Different states require different fuel blends and some (like here in Minnesota) actually require different blends throughout the year depending on the seasons. There is actually a few % change in energy per gallon between these different blends.

 

As for the FFH specifically - the Atkinson cycle engine is setup to have modified compression stroke that reduces the energy consumed by the engine in that stroke and thus a lower compression ratio. The lower compression ratio means that the octane (or compression/heat resistance before ignition of the fuel) does not need to be high for the fuel to avoid pre-ignition or knock. I have not looked at the diagrams but this engine might not even have a knock sensor because of the modified cycle. This car will not benefit at all from higher octane fuel but better quality fuel is always better for the longevity of the fuel system (quality being the proper detergents and a lack of unwanted contaminants)

 

Per Ford's documentation the car has been designed and tested for up to a 10% ethanol / gasoline mixture. Having worked on cars that were not designed for the 10% we now have mandated, I sure hope this 15% legislation that keeps popping up does not get passed - it will be a disaster. They can barely make all the components have a decent life at 10% ethanol.

 

Around here E85 is quite common. Talking to the service folks the people using E85 regularly (in cars designed for it) are seeing more fuel system problems than those that are not. Ethanol and water are a bad combination and here in Minnesota we get plenty of humidity and temperature changes that cause condensation.

 

PS: The reason Ethanol is used in super high performance race cars is that the high octane rating means that you can stuff a whole bunch of it in the cylinder on a single stroke and not worry about it pre-detonating. More fuel per stroke means more energy per stroke. More energy per stroke means more power. It actually has less energy per unit but you can cram more of it in a space and more than make up for the reduced energy.

 

Jon

 

 

 

 

 

Ethanol doesn't hurt performance as it's naturally higher octane is very good for vehicles designed to run on it. I had the opportunity to ride along in a brand new Corvette Z06 that recently had an E85 conversion done to the motor and calibrations(major motor work). I have never been in anything that fast in my life before. However, I think people meant to say that you take a significant fuel economy hit with ethanol blended fuel.

 

As for the poster who mentioned Sunoco fuel, you actually have to be very careful as their Ulra 94 octane stuff is utter crap. It uses a special additive that is blended in at the pump to achieve that 94 octane rating. Many people in the automotive world have talked about it being utter garbage in it's knock resistence as some tuners have found it to be even worse than standard Shell/BP 93 octane fuel.

[rfruth]

The FFH has a low compression ratio ? This article (link) says "The 2.5-liter four-cylinder engine carefully tweaks intake valve timing and raises the compression ratio to increase efficiency" - is this wrong ?

 

article link

[Oman]

Yep, they got it wrong, sort of...

 

..."Recently Atkinson cycle has been used to describe a modified Otto cycle engine in which the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold. This is more like a Miller cycle engine than an actual Atkinson cycle engine. The effective compression ratio is reduced"... (Stolen from Wikipedia)

 

The problem is that usually "Compression Ratio" is used to describe the power cycle part of the ratio (or the expansion ratio), which in Otto engines is more or less the same as the compression part of the cycle. In Atkinson cycle engines they are different from each other. The power cycle compression ratio (expansion ratio) on the FFH is 12.3:1 which is pretty high but the actual compression ratio (atmospheric pressure to piston TDC pressure) is considerably less than that because they delay the intake valve opening up for so long. The amount of gas compression before ignition is what matters when it comes to octane. Octane rating in fact means the ability to resist ignition when under pressure and heat. The car wants ignition when and only when the spark fires.

 

I wish they wouldn't call them Atkinson Cycle engines because there is really more to it than just dropping the compression ratio over the expansion ratio. Atkinson Cycle engines have a complex connection between the piston and the crank that actually changes the distance the piston travels on each part of the cycle.

 

Jon

 

 

 

 

 

 

 

 

The FFH has a low compression ratio ? This article (link) says "The 2.5-liter four-cylinder engine carefully tweaks intake valve timing and raises the compression ratio to increase efficiency" - is this wrong ?

 

article link

[kram1984]

They can barely make all the components have a decent life at 10% ethanol.

 

Yes my question was whether for the FFH if anyone knew if they've just made the components have a "decent" life with E10, or if it's an "equal" life to non-E10. (And also on fuel economy differences. If there's a 10% loss in fuel economy - Which I've found more than that reported commonly in other forums for cars such as the Prius on E10) essentially means all the ethanol has gone up in fumes with no benefit whatsoever and just extra weight to carry and/or causing more engine wear)

 

I figured the higher octane wouldnt help but maybe the additives or fuel quality between midgrade and regular unleaded might be different as well (Other ford vehicles have posters saying that their cars "like" unleaded plus better, of course it could just all be in their heads)

 

Guess I'll stick with shell unleaded for now... they just put up the stickers last week so unless they had ethanol in the gas already, I should be able to compare my commute easily, it's ~20m both ways with ~85% hybrid freeway driving, other 15% almost full EV mode and I get very consistent readings within the same tank of gas. Thanks all for the input.

[junehhan]

Yes my question was whether for the FFH if anyone knew if they've just made the components have a "decent" life with E10, or if it's an "equal" life to non-E10. (And also on fuel economy differences. If there's a 10% loss in fuel economy - Which I've found more than that reported commonly in other forums for cars such as the Prius on E10) essentially means all the ethanol has gone up in fumes with no benefit whatsoever and just extra weight to carry and/or causing more engine wear)

 

I figured the higher octane wouldnt help but maybe the additives or fuel quality between midgrade and regular unleaded might be different as well (Other ford vehicles have posters saying that their cars "like" unleaded plus better, of course it could just all be in their heads)

 

Guess I'll stick with shell unleaded for now... they just put up the stickers last week so unless they had ethanol in the gas already, I should be able to compare my commute easily, it's ~20m both ways with ~85% hybrid freeway driving, other 15% almost full EV mode and I get very consistent readings within the same tank of gas. Thanks all for the input.

 

 

To my knowledge, there is generally no difference in quality of fuel between the different grades. You have regular, premium, and plus which blends regular and premium at the pump to produce the 89 octane rating(87 octane for you high altitude folks). What might different are the amount of additives that are added to it. For instance Chevron stated in a PR letter to me about a decade ago that they blend their supreme with 20% more Techron than their regular fuel. Shell used to provide the same amount of additive in all fuels, although i'm not sure how things have changed since they now use their "V-Power" additive in their premium. BP to my knowledge uses the same additives, although the concentration of it may be different across the grades.

 

Ford engines are generally tuned to optimally run on the octane fuel that they were designed for. I remember that in the manual for some of my previous Fords, they actually stated that using a higher octane could actually cause problems.

 

As a general rule, you should only switch to a higher octane if you are getting engine pinging at the recommended grade, and usually there is an issue if you get excessive pinging on the correct grade fuel. My understanding is that because premium fuel burns more slowly, it can actually harm performance when used in a vehicle designed for 87 octane.

 

I think the important thing is to use a quality fuel as everyone here agrees. The lower price of discount fuels may be tempting, but people often forget that most discount fuels are only blended with the bare minimum amount of detergents required by law. Laboratory testing done by Ford, GM, Toyota, Honda have mostly concluded that the amount of detergents required by federal law is nowhere near adequate in modern engines. I know that these consumer folks on the evening news love to talk about how discount fuel is the same, but I sometimes wonder about those folks.

[rfruth]

hey June you say regular & premium are blended at the pump to produce the 89 octane so why the underground tanks at the station for the mid grade ?

[junehhan]

hey June you say regular & premium are blended at the pump to produce the 89 octane so why the underground tanks at the station for the mid grade ?

 

 

It probably depends on location, but I havn't seen a gas station in recent years that didn't blend regular and premium to produce the mid grade fuel. I can't answer why there is an underground tank for that. I can only tell you what i've been told by an old local gas station owner before he retired and sold it to some kid with rich parents, who then went out of business. Of course I don't look too hard to see whether the station i'm pulling into has separate tanks or not.

 

http://en.wikipedia.org/wiki/Gas_pump

 

"In some countries, pumps are able to mix two grades of fuel together before dispensing; this is referred to as blending or mixing. Typical usages are in a "mix" pump to add oil to petrol for two-stroke motorcycles, to produce an intermediate octane rating from separate high and low octane fuels"

 

http://www.edmunds.com/advice/fueleconomy/...93/article.html

 

""Beard: "If you have car designed to run on 87 [octane], it doesn't help to run it on higher-octane-level gas. But there are several exceptions." He said that the 3.5-liter Chrysler engines are designed to run on mid-grade gas (89 octane) and it allows them to advertise a certain peak horsepower. However, it will run well on regular gas. "The difference is very small," he said.

 

Interestingly, Mazor noted that at some gas stations, there are only two grades of gas. However, they blend the regular and premium at the pump to produce the mid-grade gasoline. This allows them to have only two underground tanks for the gas storage.""

[Oman]

I suppose the original topic got a bit lost and that was partly my fault I think.

 

Most states mandate the quantity of Ethanol or other octane boosting additives. Some allow certain additives and other ban certain ones (I'm not talking about detergents). Ethanol has three disadvantages; one is that it has lower energy than gasoline so it will give less power or mileage. Another is that it dissolves many compounds that were (and sometimes are) used in fuel delivery systems like magnesium. Third is that burning Ethanol creates a larger amount of several undesirable gasses than the equivalent amount of gasoline such as formaldehyde and acetaldehyde which means considerably more ozone.

 

On the other hand many of the other chemicals used to increase octane are incredibly nasty things that leach into the ground water and are very toxic.

 

Originally it was thought that burning Ethanol in gasoline would be "cleaner" than plain gasoline because it emits lower levels of VOCs, Benzine, and particulates. But in the end you help one thing and make another worse. Ethanol is hygroscopic so it absorbs water, which is usually but not always a good thing. Marinas carry fuel without Ethanol because there is so much water vapor around that the Ethanol will saturate and that is very bad for the engine.

 

I have a '69 Mustang and I can't always find non-Ethanol fuel. After only 4 years I have to rebuild my carb again as parts have been eaten away by the Ethanol.

 

So I think the consensus is: All modern cars are designed with 10% Ethanol in mind. Use a good quality gas station that keeps their fuel systems clean. Use the octane rating recommended in the manual. You want high levels of detergents and usually that means using a brand-name to be safe.

 

Jon

 

 

 

 

 

 

 

It probably depends on location, but I havn't seen a gas station in recent years that didn't blend regular and premium to produce the mid grade fuel. I can't answer why there is an underground tank for that. I can only tell you what i've been told by an old local gas station owner before he retired and sold it to some kid with rich parents, who then went out of business. Of course I don't look too hard to see whether the station i'm pulling into has separate tanks or not.

 

http://en.wikipedia.org/wiki/Gas_pump

 

"In some countries, pumps are able to mix two grades of fuel together before dispensing; this is referred to as blending or mixing. Typical usages are in a "mix" pump to add oil to petrol for two-stroke motorcycles, to produce an intermediate octane rating from separate high and low octane fuels"

 

http://www.edmunds.com/advice/fueleconomy/...93/article.html

 

""Beard: "If you have car designed to run on 87 [octane], it doesn't help to run it on higher-octane-level gas. But there are several exceptions." He said that the 3.5-liter Chrysler engines are designed to run on mid-grade gas (89 octane) and it allows them to advertise a certain peak horsepower. However, it will run well on regular gas. "The difference is very small," he said.

 

Interestingly, Mazor noted that at some gas stations, there are only two grades of gas. However, they blend the regular and premium at the pump to produce the mid-grade gasoline. This allows them to have only two underground tanks for the gas storage.""