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From TTAC reader Ian Opp: "With all the talk about gas prices, etc. why is mid grade still being manufactured? I understand that most cars are either biased towards reg or premium, so wouldn't it behoove us to scrap the whole idea of an 89 octane?" To which I'll add a sub-question: what about substituting an E85 pump? According to the the ethanol industry, you can get better fuel economy with ethanol than regular gas. No, really; they actually want you to believe that. Check out this study from The American Coalition for Ethanol (link to the full report at the bottom of the press release). Are you craving corn juice?
38 Comments on “Ask the Best and Brightest: Kill Mid-Grade Gas? E85?...”
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The American Coalition for Ethanol does not want people to actually read the study-the font is a size 6 and is basically unreadable!
They advocate an E20 or E30 blend. Here in Colorado, all gas is at least E10, and a company called Western Gas boasts prices consistently 5-10 cents below the competition by selling an E15 blend. In my non-E85 V8 engine I get about 1mpg better economy using the E10, although that’s somewhere inside the margin of error.
Please, PLEASE do not get rid of mid-grade gas!!!!!! At higher altitudes, regular gas is 85 octane and we need to pay mid-grade prices just to get 87! Mid-grade is all I buy!
I have no idea how it works at higher altitudes but I have never purchased mid-grade nor have I ever even seen anybody else buying mid-grade. I really don’t see the point of it
Why not make mid-grade 91, which is what European cars usually specify?
I’ll never buy mid-grade as it is. The fact that nobody buys it means that it sits in the tanks forever.
Do you really need mid grade pumps if there is a low and high grade pump?
Can’t you just pump 50% low grade, pay, pump 50% high grade and get a similar result?
Normally gas is $0.10 per grade difference. When I see high grade less than 10 cents above mid grade I will use that price difference to my advantage.
Of course my car doesn’t need high octane so in my case I’m doing more like 80% low grade 20% high grade.
Oh and why I worry about it at all is that a full tank lasts several months in my car. So I try to never fill it above half way unless I am going on a longer trip but if I end up with gas in the tank for several weeks I do notice a difference with the stale gas.
I don’t don’t mix grades every time I fill up. I just save that concept for as the need arises.
Now on the Exx% if there is E85 and E10 at the same station you can mix your own ratios.
So if you have a 13 gallon tank and are near empty and you want E30 or there abouts why not pump 8 or 9 gallons of E10 and then 3 to 4 gallons of E85?
Mid-grade fuel began as, and always was, a marketing gimmick. It’s a classic iteration of an old marketing trick of offering three price points in order to increase overall sales.
Many consumers will be attracted to a mid-tiered product because they view it as a sensible compromise between the costly premium product and the low-end cheaper product — they buy based upon perceived value. A few customers will be drawn to a premium product because they want “the best” — these buyers are drawn by the perception of quality, and happily pay the most because the pain of paying more provides evidence that they care most about quality. A few more will be pushed toward the lowest product because of their desire to save money — these buyers want to feel that they are savers.
The overall result: happier customers across the board. The value, quality and saver crowds all believe that they got the better end of the bargain. Most of them seem to confuse octane levels with fuel quality, and presume that more is better, when the average car will run just fine on regular gas and that only a few actually require premium.
It may be becoming less important, as high fuel prices tend to turn more of us into savers, but there isn’t much reason to get rid of it now, because it’s just a blend of regular and premium, so providing it doesn’t add much to the fuel station’s costs.
I’ll never buy mid-grade as it is. The fact that nobody buys it means that it sits in the tanks forever.
As noted above, midgrade is just a mixture of premium and regular, blended at the pump. So don’t worry, your midgrade fuel won’t be stale. But you still probably don’t need it. http://www.edmunds.com/advice/fueleconomy/articles/106293/article.html
At the risk of thread-jack: I say, kill ethanol blends, period.
Boondoggle: “a wasteful or impractical project or activity often involving graft; the acquisition of gain (as money) in dishonest or questionable ways”. Sounds like a perfect description of U.S. grain-based ethanol production to me.
1) The energy input to produce grain-based ethanol does not equal energy output from the fuel produced. It’s both a waste of energy and topsoil.
2) Without massive artificial support, corn and grain based ethanol wouldn’t be economically viable… “my country ’tis of thee, sweet land of subsidy…” feh.
3) I’m tired of seeing my grocery prices continue to skyrocket so some fatass can drive their Escalade on the cheap.
I’m sorry if I’m peeing on anyone’s hideously expensive corn flakes, but grain-based ethanol production is a stupid and wasteful plan for U.S. energy independence. I’d be glad to see it go away.
Hmm – the American Coalition of Ethanol submits a report with their own testing – yep, no bias there.
Kill E85 blends? Hell yeah.
Kill mid-grade? What the hell for? I know a number of Volvo’s require mid-grade gasoline, and it’s not like it uses it’s own storage tank or anything.
Unless you live in Utah, where the grades are 85 – 87 – 91. I do run midgrade here, but that’s just to get the minimum 87. I can’t afford any power loss in my daily driver Hyundai Accent — now don’t laugh, it’s paid for.
I’ve never quite figured out why they run lower grades at our stations here.
drooartz:
I used to own a Hyundai Accent, and I took it on a road trip across Canada. I understand completely your concerns about power loss in the Accent… going up some mountain roads, I lost about 50km/h of speed, all while having the gas pedal floored.
Organizations that commission studies get the results they paid for. A recent Prime Minister had a poll saying 93-percent of Canadians wanted a gigantic new tax!
Yesteryear’s posted ratings stated premium was 100+ octane, mid-grade 95, and regular 92. Cutthroat competition drove octane ratings down and prices up!
Nonetheless, premium merits consideration where government mandates ethanol content. Some retailers meet the required average, usually 10-percent, by concentrating ethanol in the lower grades leaving premium uncontaminated. The reduced fuel consumption inherent in ethanol-free premium offsets some or all of the additional cost.
Does anyone remember those old gas pumps that had a dial where you could select the blend before pumping to get your desired octane number? You don’t get that kind of choice anymore.
I buy mid grade if I’ve got a half tank of 93 or 92 octane (the WRX needs 90). Saves me a couple bucks without the power loss.
Gardiner: Why would retailers mix ethanol with low grade gas? Ethanol has an octane rating somewhere north of 100. With the lower price of ethanol (I see E85 at $2.25) they would get a better return by mixing ethanol with premium. Hell, I sometimes see mid grade cheaper than regular because of the ethanol blend.
beater: Ethanol from grain yields about 1.25 units of energy for every unit required to produce it. Not a great ratio but not a loss either. And do you not think the increase in petroleum prices might have more to do with increased food prices than corn prices?
@benders: Increased petroleum cost will most certainly affect food prices across the board, but the startling rise in the price of grain over the last few years has been attributed to the demands made by ethanol production, at least from what I’ve read.
I could well be off in my assumptions about the energy yield of ethanol from grain. In the statistic you cite, what are the inputs that are measured to come up with that figure? I would assume that at a minimum they would include fuel used for cultivation, harvest and transport, as well as fertilizer use. What about water use and demands made on the land and topsoil? In other words, were all required inputs for production truly and accurately measured? My inner skeptic still wonders if some of the less tangible and long-term costs were truly considered.
I’ll cut this off at this point as I am again wary of thread-jacking, but I’d suggest that the subject of the true costs of ethanol production as currently practiced in the U.S. might be a worthy subject for further discussion here on TTAC.
As for mid-grade fuel, the few times I’ve used it to avoid preignition and knocking problems were followed by a bit of judicious tuning which usually resulted in my being able to go back to 87. Mid-grade’s a nice option to have when you need it, though.
The Ninjalectual :
March 22nd, 2008 at 11:00 am
Please, PLEASE do not get rid of mid-grade gas!!!!!! At higher altitudes, regular gas is 85 octane and we need to pay mid-grade prices just to get 87! Mid-grade is all I buy!
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drooartz :
March 22nd, 2008 at 12:10 pm
Unless you live in Utah, where the grades are 85 – 87 – 91. I do run midgrade here, but that’s just to get the minimum 87. I can’t afford any power loss in my daily driver Hyundai Accent — now don’t laugh, it’s paid for.
I’ve never quite figured out why they run lower grades at our stations here.
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Actually, with the altidude in Colorado and Utah, 85 octane is equivilent to 87 octane at lower altitudes. I read something about years ago in the paper where they cleared that up. You can Google the info as I am not the expert. Yes, I used to use 87 octane when I first moved to the area, but seeing that 85 octane made no difference in performance, I’ve stuck with 85 ever since. Give it a try. Especially with gas stations in Denver metro starting to post only their prices for 85 on the street sign, which now conveniently allows them to gouge on 87.
Most stations mix Regular and Premium at the pump to make Mid-grade. There usually is no separate tank.
My Father used to work for Sun Oil back in the 80’s & 90’s and they used to have 5 grades of gas (at least in the Mid-Atlantic) 86, 87, 90, 92, & 94 octane. He used to tell me that the pumps weren’t accurate enough to blend the 87 so essentially you got 86 and the station made a little extra profit.
While Ethanol fuel is made from Corn, all Exx blends should be scrapped. It is quite possible that by switching to another form of ethanol production (such as cellulose) that this would become viable, but until then all blends should go and so should all associated CAFE ‘discounts’ for E85 capability.
As for mid-grade gas, I’m with the previous poster who suggested that the pump should be able to mix that on the spot with standard and premium gas (if it doesn’t already). Since it isn’t subsidized by the government (like Ethanol) I guess the market will decide if it’s viable or not.
a: Midgrade fuel is mixed at the pump, the pump just mixes the 87 and 91 octane together.
b: My car needs midgrade. A lot of cars may be specced for 87, but due to wear, sensors dying, or just cruddy manufacturing, they need 89 to not knock.
Actually, with the altidude in Colorado and Utah, 85 octane is equivilent to 87 octane at lower altitudes. I read something about years ago in the paper where they cleared that up. You can Google the info as I am not the expert. Yes, I used to use 87 octane when I first moved to the area, but seeing that 85 octane made no difference in performance, I’ve stuck with 85 ever since. Give it a try. Especially with gas stations in Denver metro starting to post only their prices for 85 on the street sign, which now conveniently allows them to gouge on 87.
With increased altitude, pre-ignition tendency is reduced. In the old days, we would advance our ignition when we hit the Rockies. That’s why you can use lower octane gas.
Having perused that ethanol report I find that it is quite simply fraudulent, and the study upon which the report is based is heavily biased in it’s declarations (or lack thereof). Let’s review their “key findings”.
“Ethanol’s energy content was not found to be a direct predictor of fuel economy.”This is of purely academic interest, giving no indication of any benefit over straight gasoline.
“E20 and E30 ethanol blends outperformed unleaded gasoline in fuel economy tests for certain autos.”This is in fact CONTRADICTED by the evidence in the study, for all vehicles except the flex-fuel Impala. The Toyota and Ford each may have gained 1% in fuel economy using E30 over straight gasoline, but 1% seems to be well within the (undeclared) margin of error for the tests so it is not a scientifically significant result. Besides, that is only the result for the highway drive cycle. In the city cycle they each lost a statistically significant 6% and 8% efficiency, respectively. The non-flex Impala burned 8% and 5% more fuel in highway and city drive cycles when run on what the report calls the vehicle’s “optimal” ethanol blend. The flex fuel Impala did impress by gaining 15% and 14% fuel efficiency over straight gasoline by using E20, but it suffered a 24% loss on the E85 highway cycle. Of course, by now the credibility of the entire report must be questioned.
“Standard, non-flex-fuel vehicles operated well on ethanol blends beyond 10 percent”That claim is simply pulled out of thin air. The study only states that they stopped tests using higher concentrations of ethanol in the fuel when the check engine light would come on under full engine load. That is a long, long way from saying that the vehicles operated well on any fuel (they ran Chevys fer cryin’ out loud!) and says nothing about the effects on the longevity of the engine.
Paul Niedermeyer :
With increased altitude, pre-ignition tendency is reduced. In the old days, we would advance our ignition when we hit the Rockies. That’s why you can use lower octane gas.
I’ve wondered why the pumps had lower octane here. I’ll have to try the 85 and see if I notice any difference. Thanks all here for the inputs…
I certainly hope that “the powers that be” don’t remove mid-grade pumps. Not all stations around me carry it now. One of my cars pings with 87 but is fine on 89 octane. I don’t want to have to pay extra for 91 unnecessarily. Unfortunately, my point of view is probably in the minority.
My car specifies 89 octane. 1998 528i
Actually, the reason normally aspirated cars don’t need as high octane at altitude is that the air charge is less, thus effectively reducing cylinder pressure.
Think of it this way, if you have a 10:1 compression engine, and the air pressure at sea level is about 14.7 psi, then in the engine it gets compressed to 147 psi. If you’re at 10,000 feet where air pressure is about 10.1 psi the cylinder pressure at full throttle is only 101 psi. Effectively you’re driving with the same power, engine pressures and ping possibilities as if you were at sea level but the engine compression was only 6.8:1 – a very low compression engine that would not need much in the way of high octane.
Now IF you drive a vehicle with a turbo or supercharger that is able to keep the intake air charge as high as if the car was at sea level, you’ll need the same octane at altitude as you do at sea level. It’ll just be harder to find the high test gas.
Mike66Chryslers are you unwilling to pump half of one grade and half the other?
I don’t know about you but when I’m pumping I use “pay at the pump” with a credit card and it doesn’t cost me more than 30 seconds to switch grades during a fill up.
Besides if you watch for it you might find the (high grade + low grade)/2 cheaper than the mid grade on the same pump.
I suppose you could argue the station would price it differently if the mid grade wasn’t there but I see stations in my town that have 2 low grades and 1 premium on the same pump and their premium prices aren’t abnormal compared to the other stations.
beater: Here’s my source for ethanol production efficiency: http://www.pnas.org/cgi/content/full/103/30/11206
I’ll suggest reading this to actually see the impact commodity prices have on food prices. http://www.ers.usda.gov/AmberWaves/February08/Features/CornPrices.htm
alanp: Your math is good but your theory is off. A compressed gas gains heat which in turn raises the pressure. So a 10:1 compression engine will have a pressure of about 370 psi at TDC prior to ignition (assuming isentropic compression). At 10,000 feet, 255 psi; equivalent to an engine with a 7.7:1 compression ratio at sea level.
Benders – my math is a bit off – my theory is just fine. As I stated the need for premium is lessened by the lower pressures in the combustion chamber. I did not figure in the heating of compression, but the idea still stands that because there is less pressure a lower grade gas will suffice. That’s why Normally aspirated engines work just fine at altitude with lower grade gas. Whether the effective compression goes down 23% or 32% either way it’s a LOT lower. As is the total fuel/air charge and the resultant power.
lprocter1982 :
Kill mid-grade? What the hell for? I know a number of Volvo’s require mid-grade gasoline, and it’s not like it uses it’s own storage tank or anything.
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i don’t think many volvo’s require 89 octane. the owner’s manual specifies 91 octane. however, i use 89 in mine and i know a lot of other volvo owner’s do, too. i can’t tell the difference in performance or mpg so i figure i might as well save .20 /gallon. if you run it on 87 octane you will get noticeable worse mpg and some volvo owners report knocking and performance problems. so, please don’t take my 89 away!
@ dhanson856:
You make a good point. I’m a pretty thrifty guy, but I never thought to look at whether stations are charging higher than the difference between 87 and 91 for 89 octane. I’ll pay more attention to that in future.
Since you asked, my wife likes using pay-at-the-pump for gas but I don’t. (I also don’t like the self-serve checkouts at Home Depot.) I suppose if I get stuck switching fuel grades mid-fill to get my 89 octane, pay-at-pump would be the only way it wouldn’t be a PITA though.
Even without stopping mid-fill, refuelling my cars is not something I enjoy, and not just because of the cost. The location of the fuel filler neck, behind the rear licence plate, is one of my only pet peeves with the 1966 Chrysler. It’s way down low, you have to wrestle with the spring-loaded licence plate, and there’s nowhere convenient to put the gas cap while filling. If you’re not listening for the change in “gurgle” when it’s almost full and partly release the filler nozzle, fuel will shoot out and spill on the ground.
I’ll never buy mid-grade as it is. The fact that nobody buys it means that it sits in the tanks forever.
Mid grade is made from blending in the pump. They really only hold low and high grade. Sunoco used to have selectable blends on their pump all the way to 100+ Sunoco 260. Nice pink stuff, smelled like lighter fluid. crack cocaine for piston heads.
I have experienced about a 10% increase in efficiency using 87 octane (mid-grade) over what I get with 85 octane (regular) in Colorado at 6,000 feet and above. Mid-grade costs about 3% more–I think I’m coming out ahead in this deal. I have not tested 91 octane (premium) enough to have an opinion on how that affects my fuel consumption.
The 10% rule applies across all cars and trucks I have owned in the ten years I’ve been measuring. Granted, when you’re getting 17mpg in the V8 Tundra I drive now, 10% is a little over a 1.5 mpg difference. That seems dangerously close to the margin of error, and I do my best to control for the variety of driving conditions I see, but with the large sample size I think this can be considered a fact.
I did not realize that mid-grade is simply a mix of regular and premium. I am now wondering if there is a cheaper mix of the two that I could use to eek out another mpg or so… I will have to look into it.
I think ethanol gets a bad rep because of the subsidies. Corn ethanol has problems, but do not dismiss ethanol altogether. Sugar ethanol is powering Brazil’s growing economy. And while celluosic ethanol may never be viable, gasification is far more mature and versatile, able to produce liquid fuel from just about any source of long chain carbon, including trash.
In Nebraska and Iowa,”mid grade” is NOT a blend of regular and premium but a code word for E10.
Also, this alleged “mid-grade” costs 10 cents,or 3% less than regular, but in both my machines yields 10% less mileage. Not a winning proposition in 3 seasons. I buy it anyway in winter and skip adding HEET–no gas line freeze yet.
BTW, back in the days of the old 4-way Conoco pumps, a pump jockey (this was before self-service was legal) got confused and put 11 gallons the bottom grade, not the top one, into the 20 gallon tank of a car that called for premium fuel.
When nothing bad happened as a result, I started buying the 3rd grade, rather than top grade, and eventually got up the guts to drop to the 2nd grade on a near-empty tank, which did make the car knock.
From then on, I tried to buy gas at 1/2 full and to alternate grades 2 and 3 to make de facto 2 1/2.
wow, center fuel cap behind the license plate. That is the best possible reason to avoid switching grades mid fill up.
I hadn’t even considered the possibility someone still had to deal with that.
Anybody know if rear fuel fillers are no longer allowed to be made in the US or is it a voluntary design change?
One of the interesting things to know is that “mid” grade is NOT 50% premium and 50% regular. It’s more like 75% regular and 25% premium. So it usually IS possible to save money by blending your own mix.
I buy midgrade instead of having to put premium in. Its a good way not to have the knock sensor kill performance or have the valves knock by using lower grade gas in higher compression engines.
oh and for the record the 3 grades I see here are 87 89 and 93.
So for example I might see
$3.13 for 87 octane
$3.23 for 89 octane
$3.33 for 93 octane
1) The blend of low grade and high grade to get your mid grade is dependent on the actual octane levels of the low and high! For example, if you have 87 and 93, then you blend 60% low grade and 40% high gives you a mid grade 89. Some gas stations blend mid grades on their own–others buy mid grade from the terminal. But the terminal blends mid grade this way as well.
2) Ethanol has a higher octane rating, but a lower energy content than gasoline. That means that it pings less, but it will give you a lower gas mileage. E85 yields about a 30% decrease in gas mileage over pure gasoline. Generally most people cannot detect the gas mileage difference between pure and E10. This is evidenced by those who believe that they get more gas mileage with the E10. The laws of physics generally contradict this result.