Brand of gas and fuel mileage

bosip

Contributor
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Mazda CX-5
Has anyone found a difference in their gas mileage caused by the brand of gas they are using? I am not real happy with my gas mileage right now -- averaging about 24 with 40% highway, 60% city and the dealer tells me that the two causes are the winter blend gasoline and also warned only to use name brand gas. In our area we do have some Gulf and Sunoco stations but the only high tier gas in the area is Shell which is usually about 20 cents more per gallon for regular. We also have many Supermarkets and convenience stores such as Wawa, Turkey Hill. 7-11 etc. who sell generic gas. The dealer said do not use these as it will reduce your mileage. I have been using a combination based on where I am when I need gas. Just wondering what anyone's experience has been with this,
 
It may be other factors but for me I've noticed the best mileage with Shell. I go for the top tier stuff for the CX5 because of the high tech-ed-ness of the engine and have noticed it is much easier to keep the mpg up around the 30-31 range when using shell (the 87 stuff). When I fill with Chevron it doesn't seem to do as well. I seem to have to really watch my driving style with other gas in it.

There are a lot of other things that do affect mileage so it may just be in my head. Especially since if I get in just a little bit of a hurry in my commute the mpg can quickly drop to 28 and if I get stuck in flowing traffic going under 60 it really climbs.

Those numbers are calculated based on gas in and miles driven not the dash display.

I know the 'better' gas will keep things cleaner but I'm not sure how it could actually have a fairly quick effect on mpg so I keep thinking I'm just imagining it. Maybe more or less Ethenol blended in?

The winter blend gas took away what I thought would be a mpg increase from not using the A/C (or having the windows down) in the summer.

I've also played around with drafting behind semis (at a safe distance) but also can't tell if the level looking road might be ever so slightly downhill when I'm behind them to see what difference it makes. But several times I've been behind one doing around 60 and the instant readout is in the range of 41 or even higher. I keep forgetting to find some good landmarks when I'm behind one so I can try the same section the next day without drafting.

I do notice when it is windy out my mpg seems to drop. I think as we push the limits of fuel efficiency it is easier for any of the factors to make a noticeable difference.

Trevor
Mazda CX5 Accessories, oil and filters
 
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Brand of gas definitely affects performance!

It is especially noticeable if you are driving a low powered, manual transmission car. That is not to say the effects are not there for automatic transmission cars, it's just less noticeable from a driving dynamic perspective. Whenever I used anything other than Chevron, my cars became sluggish and unresponsive. This includes Shell! Chevron is the only brand of gas I will use in my cars now.

BOSIP, from what is available in your area, maybe it's not an option for you. Others, try it!
 
I work for Shell. I have left my input here in the past, but it typically goes ignored.

As long as you buy from a branded filling station that has a lot of throughput, you're getting perfectly good gas. You won't see a mileage difference between brands.
 
I for one agree with IHeartG, so we don't ignore you. However; I might add, that if you use an off brand fuel for a long time, you may suffer due to a fouled up fuel system.-lack of cleaning additives. Ed
 
You might want to browse this site: http://www.toptiergas.com/index.html

We have an "off brand" chain here in Wisconsin, Kwik Trip, which guarantees that all of their gas is Top Tier. They are listed on this site's listing of top tier retailers.

It is also true that gas with a 10% ethanol content has less energy per gallon and will decrease gas mileage accordingly. However it is very difficult to find 87 Octane that doesn't have ethanol. You can check at the following link.

http://pure-gas.org/
 
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I agree with IHearGroceries and I'm glad he's provided input based on his experience actually working at Shell.

I use nothing but Chevron regular in the CX-5 and Chevron premium in my other 2 cars, no problems.
 
Has anyone found a difference in their gas mileage caused by the brand of gas they are using? I am not real happy with my gas mileage right now -- averaging about 24 with 40% highway, 60% city and the dealer tells me that the two causes are the winter blend gasoline and also warned only to use name brand gas. In our area we do have some Gulf and Sunoco stations but the only high tier gas in the area is Shell which is usually about 20 cents more per gallon for regular. We also have many Supermarkets and convenience stores such as Wawa, Turkey Hill. 7-11 etc. who sell generic gas. The dealer said do not use these as it will reduce your mileage. I have been using a combination based on where I am when I need gas. Just wondering what anyone's experience has been with this,

You never know what you are getting.

In my area Shell is not as good as Chevron in my CX-5 or in my Volvo or Ducati motorcycles. The one time I filled up with Union 76 my mpg took a big jump (but the 76 station is not located along my usual route).

Yes, there are differences between fuels but they cannot be applied with blanket statements for or against particular brands.

You fill up and take your chances. Some of the cheap, no-name stuff is just as good.
 
Third party and exchange business puts Shell, Chevron, Exxon, etc. gas in mom n pop, unbranded gas stations, and also puts Shell gas in Chevron stations, or Exxon gas, in Valero's stations, etc.

The difference? Detergent additives. That's it. I will say that Shell puts a significant amount more of their proprietary additive into their fuels than anybody else, particularly their premium. Branded proprietary detergents are generally all perfectly adequate (no matter the particular brand) for filling your car for the duration of its lifetime. If you want to argue that unbranded fuels are not as good over an engine's lifetime, I will buy that. But, I will also add that in our (or any) DI engine, half of the detergent's purpose goes unused, as the valves never see any fuel wash over them. An unbranded gas station dispenses fuel that has been additized with a generic additive, which typically only meets emissions mandates, and is injected at a very small rate. FWIW, you get what you pay for.

I fill up with either Shell or QT exclusively. If I am out of town, or in an unfamiliar area, I'll find a Shell. But, I'll maintain that quality issues in fuels stems from arbitrary PQA lapses, or low throughput at the filling station, where there is a larger window for contamination or degradation to occur.
 
The only real difference i noticed was when I put in no-ethanol gas from a supplier instead of the normal 10% ethanol gas from gas stations.
 
Gas is gas to a point, all manufactures have to make gas (at least here in Canada) to work in every kind of gas engine. Gas has to be so universal and can not stray from that line very much because of this. The only thing that most companies add are additives and cleaners which do not effect millage but help keep the engine clean. Esso cannot make a different fuel then Petro Canada because all engines are meant to run this fuel, from a lawn mower to a full car. If they could they would sell that to you and shove it down your throat as fast as they could because if they could say you get 25 more per tank form their gas then the competitors, believe me you would know it.

Welcome to marketing 101, the big name company makes you think their gas is better when it is the exact same stuff at the no name gas bar beside it other then cleaners in the fuel or lets say no water in the fuel cause of good stations and properly installed tanks under the station that your money pays for!! Just do a little research, the gas even comes from the same refinery as the big guys for some companies!
 
Esso cannot make a different fuel then Petro Canada because all engines are meant to run this fuel, from a lawn mower to a full car.

This is simply not true. It is true that fuels are mandated to meet certain standards. It does not follow that all fuel is refined to the same exact product. It definitely varies in specification. The trouble when we buy fuel is there is no way to know which refinery the fuel came from or whether it is at the high end or low end of various specifications and how long the fuel has aged (and under what conditions).

And I am sure that some batches that are outside of specification (or become that way through aging) makes it's way into the system. I have Italian motorcycles designed to run on premium (high octane) gasoline and it is especially easy to notice how the engine runs somewhat differently on fill-ups from different retail outlets even though it is all labeled "premium unleaded". But it is not consistent from year to year. Sometimes the station with the best fuel one year will have the worst the next. The point is, fuel does vary in specification.
 
I have watched and read to many reports that say different. here are a few for reading

http://abcnews.go.com/GMA/Business/story?id=2978563&page=1
http://www.essortment.com/automotive-tips-gasoline-brands-different-41980.html

Everyone had been marketed to and that is why they believe they are getting something for their dollar. People want to believe they can see through marketing but they cant in most cases. Take for example Tylenol lets say its worth $10 a bottle but the no name brand next to it is $5, what one are you going to buy? Well some people don't like paying higher prices so they go with the cheaper brand. Now Tylenol goes on sale and is now $5 a bottle, now what do you buy. Statistic show that 90% of the people that would buy the cheep brand now that the name brand is the same price would buy the brand name because they think they are getting the better brand. what if i told you that drug are so regulated that once cant be different from the other 250 MG of Acetaminophen has to be the same and is regulated by a regulatory body. The only thing that differs between Brand A and Brand B is fillers the stuff that makes the pill! so tell me why people do this? because they have been marketed to their entire life by Tylenol that's why, the no name brand does not market them self so we feel like Tylenol is the better buy when it is the exact same thing. Fuel manufactures follow something called the "ASTM D4814 - 11b Standard Specification for Automotive Spark-Ignition Engine Fuel" have a look and see that they all have to produce gas that meets these standards and it's not exactly easy to do it in a different ways as no one has (from my reading) a trademark way of refining fuel that gives a better product.

I am not saying there is no difference in gas I am say the difference is so minor you will never see a difference in fuel millage from tank to tank. Now your engine might be cleaner because they add expensive detergents which in turn will keep your engine running better and give you better fuel mileage over a course of 1-2 years. But that is a different statement then the one that was originally asked "If I buy a tank of Brand A will it give me better fuel millage then Brand B" and the answer is no it wont.

I am not saying I am absoloutly right I am saying be informed and make informed choices!
 
FYI, it looks like fuelly.com finally has 2014 Mazda CX-5 available!
 
FYI, it looks like fuelly.com finally has 2014 Mazda CX-5 available!

Yes, I signed up yesterday since I have yet to need a fill up so I'll be tracking my usage from day 1!

As to the OP, I've heard the Gulf is not the best since they purchase unbranded product. Don't know if this is still true. I usually fill up with Hess, Sunoco or Exxon/Mobile. I'm a shareholder of XOM so might as well contribute to my own dividend and this eases the pain at the pump. Won't patronize BP since the spill in the gulf, my way of making a political statement.

Going from a 6 cyl/premium only vehicle, I will surely appreciate the fuel efficiency of the CX-5!
 
I buy my gas at Kroger. Prices are better than average and if you calculate shopping discount (3-30 cents a gallon) that's by far the cheapest gas in my area. Also, it helps that Kroger gas stations are very high volume.
 

Both of the articles you provided links to admitted that gasoline does vary somewhat from station to station. But the second article was a joke because it was written by someone with strong opinions yet not one source was cited. You cannot bolster your opimion with another laymen's opinion.

The ABC article is a joke (as is most media reporting on any subject in which you know more than the journalist). The primary problem was that they only tested one sample of fuel from only two stations. While they only found minor differences in the fuel, they then appear to conclude that this demonstrates all fuel from all stations is essentially equivalent (in terms of MPG and engine health). Such an unfounded conclusion with such a miniscule sample size is a disgrace to any real reporter.

My opinion that fuel has significant variation (but it is not consistently better at any one station from year to year) is also not very scientific. It is based upon my personal experience. Since I often run my cars down to empty (less than a gallon left) and my motorcycles also (less than a quart left) I can often feel the different running characteristics of the newly purchased fuel as I drive/ride away from the station. If I fuel up and drive/ride away as soon as i start the engine I am often up to speed and cruising at a steady state when the new fuel hits the system. About 20% of the time I can notice the difference. This is especially true on my motorcycles which call for 95 RON but I have noticed it with the CX-5 as well. In my opinion, there is no doubt that fuel can and does vary enough to affect mpg, power and smoothness of running of some vehicles.

And this is without even getting to the fact that some regular unleaded has 10% ethanol while some regular unleaded is ethanol free. If you don't think that's going to make a difference then I have a bridge to sell you.
 
Since I often run my cars down to empty (less than a gallon left) and my motorcycles also (less than a quart left)

Do you change your fuel filters on a more frequent basis since you're apt to be sucking up more of the contaminants at the bottom of the tank?
 
Do you change your fuel filters on a more frequent basis since you're apt to be sucking up more of the contaminants at the bottom of the tank?

I've heard that one before but always wondered about it because the gas is always being sucked from the bottom of the tank. I guess if the contaminants are ones that float then it would take in more of them but I'd think most of the bad stuff in the tank would be at the bottom all the time.
And do modern gas tanks have that problem as much? On older cars you'd get rust in the tank but on new cars? And how much junk is ending up in the storage tanks at the stations? Is that also improved over years past?
A lot of cars anymore don't even have fuel filters, they just have the strainer on the fuel pickup in the tank.
 
Do you change your fuel filters on a more frequent basis since you're apt to be sucking up more of the contaminants at the bottom of the tank?

No, I just change them on the factory schedule or, on my Ducati motorcycles, about 150-200% of factory schedule since the fuel filter replacement interval is only 12,000 miles and I live in a wet(not dusty) climate.

And, I agree with ta240, the pick-up is near the bottom of the tank and fuel is sloshing around in there anytime your tank is below half full and the road is bumpy so it's all getting mixed up anyway. Plus, the modern evaporative emission systems on tank breathers help prevent condensation in the tank. That, coupled with fuel tanks more resistant to corrosion and ethanol in the fuel has virtually eliminated rusting tanks. The ethanol absorbs any water that does manage to condense on the tank walls and burns it gradually. This can actually increase MPG in the same way that water injection can.

Never had to replace a fuel pump and I keep my cars (and motorcycles) a long time.
 
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