Gasoline: Shell, Mobil, Valero, Oh My!!

[PGrated]

Here in the Northeast, many or all of the Mobil stations have been sold off to Valero.

I am usually pretty picky about the gas I put into My G35. I usually stick to either BP/Amoco, Mobil or Shell. Always 93 or better octane. Now, Valero is the new guy on the block. I was just wondering if anyone has had any good or bad experiences with their gas; and if its a decent brand to consider buying.

Valero is cheaper by about 4-5 cents per gallon than BP/Amoco. But, in the long run, I would rather spend a bit more money on better fuel than have problems with the car later.

I remember many years ago, BMW used to do tests on the quality of gasolines and would publish its findings on which ones were considered the best, cleanest, etc. I have not seen anything like this in recent years from them.

Thanks for the help.

pgrated.

[ezflow]

Here in the Northeast, many or all of the Mobil stations have been sold off to Valero.

I am usually pretty picky about the gas I put into My G35. I usually stick to either BP/Amoco, Mobil or Shell. Always 93 or better octane. Now, Valero is the new guy on the block. I was just wondering if anyone has had any good or bad experiences with their gas; and if its a decent brand to consider buying.

Valero is cheaper by about 4-5 cents per gallon than BP/Amoco. But, in the long run, I would rather spend a bit more money on better fuel than have problems with the car later.

I remember many years ago, BMW used to do tests on the quality of gasolines and would publish its findings on which ones were considered the best, cleanest, etc. I have not seen anything like this in recent years from them.

Thanks for the help.

pgrated.

If that's important to you, go to the 'top-tier' gas website. It is endorsed by BMW, as well as many other auto manufacturers.It does not mean if you get Costco gas your engine will rot. (Because Costco does claim to use 76, Phillips, or Shell depending on the area) but it does provide you with the major makers who explain the importance of quality gas regardless of octane rating.It's a good general guide. When in doubt, stick with name brand stations with a high turnover, you should be okay IMO.

[telcoman]

I now have almost 14k miles on my 2006 G35 6sp manual Sedan. It came with a full tank of gas & if the dealer filled it with premium that was the only premium my car ever had. I read the owners manual that stated to use premium. I tried regular 87 octane when the new car had 3/4 of a tank. I filled it again with regular at 1/2 tank. I never noticed any difference in performance and have been filling it with regular 87 octane ever since. I use BP and I use Raceway or Pittstop whatever is cheaper here in Central New Jersey.My previous vehicle was a 92 Lexus ES 300 and I used reqular for 14 years & never had a problem. The oil companies would like you to believe that premium is better for your car but for most users that is a myth. IMHO save your money on gas use regular & enjoy a meal at Mastoris Diner

[SVTCOBRA]

When in doubt, stick with name brand stations with a high turnover, you should be okay IMO.

I'm with ezflow on this! Had a BAD experience with a mom&pops type gas station years ago. I stick with PB/Amoco gas. I would also use only prem. I hate that pinging noise!!!

You have a G!! Treat it nice!!!! Oh, IMHO......

[WESIDE]

Premium Chevron with techron for the win.

[ezflow]

I'm with ezflow on this! Had a BAD experience with a mom&pops type gas station years ago. I stick with PB/Amoco gas. I would also use only prem. I hate that pinging noise!!!

You have a G!! Treat it nice!!!! Oh, IMHO......

I doubt you would hear much pinging. The ECU will retard the timing if knocking is detected by the knock sensors. But the engine will not be operating at optimum performance. Makes one wonder why someone would believe anything the owner's manual says, but thinks when it says to run premium that are not serious.

Also makes me wonder why anyone would buy a performance car and run it with the same octane rating fuel for a small car with a low compression engine. You don't have to be an engineer to understand the difference.

[johnmully]

Well I read a report that all the big american auto makers when doing car tests they use chevron with techron! The catch is they don't have any in detroit (then) so they would truck in gas from another state!!! I always use premium because the g35 has a higher compression ratio than norm. My old vette had crap gas put in it once and it just ran crappy. In theory if the octane is higher the explosion is greater and as a result makes more horses. Which should give you better mileage! I have seen dyno results that show on a turbo car there is a significant rise in horsepower(25hp). Check out aps on their dyno chart, granted it is a turbo car but 3 octane made 25hp more. With the anti knock sensors it will eliminate it but if it wasn't there you would know. Go up a big hill in 6th and floor it and see how sluggish it responds. Thats when you'll notice the knocking if there weren't sensors. If you drive like a old woman you can put tequilla in for that matter and you wouln't notice. Oh if you do drive like that then why the heck would you own a G, go buy a buick and do 50 in the fast lane so I can honk an curse at you when I pass with my 93 octane!

[PGrated]

Thanks for the great info!!

Interestingly, on my way home the last few days, I've noticed that I really don't have many choices in gasoline brands. BP/Amoco, and Valero (all the converted mobil stations) are the only ones that I would consider since they have a high turn-over rate on their fuels. I agree that it is a good idea to stay away from the stations with a low turn-over rate of their fuel supply. Chevron isn't even around or convenient.Oh well, no reason to worry about it if it isn't available.

Speaking of Techron; I used to add this to my gas frequently with my other cars. I probably should consider adding it to the fuel to keep the system clean...I think it used to be every 3000 miles. Anyone have any thoughts on this??

Thanks again!!pgrated

[redhed]

an engineer over at allpar.com told us that you can't even buy the gas that is used to certify engine output.

[Q45tech]

Kind of like wine which vintage you buy:

Don't assume that the gasoline in the station tanks is necessarily made that day and every day by the same refinery. All gasoline is fungable and mixable as needed. When the tanker truck fills up a splash of marketing secret sauce is added to generic to make it the station label brand.

Sometimes the driver forgets or loses his eyedropper.

Bayway Refinery (ConocoPhillips), Linden, New Jersey 230,000 bpd Eagle Point Refinery (Sunoco), Westville, New Jersey 145,000 bpd Paulsboro Refinery (Valero), Paulsboro, New Jersey 160,000 bpd Perth Amboy Refinery (Chevron), Perth Amboy, New Jersey 80,000 bpd Port Reading Refinery (Hess), Port Reading, New Jersey 62,000 bpd

Marcus Hook Refinery (Sunoco), Marcus Hook, Pennsylvania 175,000 bpd Philadelphia Refinery (Sunoco), Philadelphia, Pennsylvania 335,000 bpd Trainer Refinery (ConocoPhillips), Trainer, Pennsylvania 185,000 bpd

[nissan_blood]

I always go Mobile or shell. Other ones I dont like just because they dont have 93 arround here best they got is 91 in most stations arround here

[telcoman]

Here in Central New Jersey I see the same Island Transportation Tanker Trucks at many different branded stations. Even Hess which used to have their own trucks now have Island Transportation trucks filling their tanks.Our reg gas prices fell to $1.98 gal today. Within 2 miles of where I live, I have BP, Hess, Lukoil, Shell, Raceway, and Pittstop. I use whatever is cheapest. Consumer Reports as well as government tests conclude that for most vehicles regular 87 octane is fine. I have never heard a ping on my 2006 G35 6sp manual. It runs just fine on regular. For those that feel better in using premium thats fine but I think its just a waste of money. We are all driving a depreciating piece of metal. Don't get me wrong, I love the G35 but in ten years I'll probably be driving something else?

Telcoman

[ezflow]

Here in Central New Jersey I see the same Island Transportation Tanker Trucks at many different branded stations. Even Hess which used to have their own trucks now have Island Transportation trucks filling their tanks.Our reg gas prices fell to $1.98 gal today. Within 2 miles of where I live, I have BP, Hess, Lukoil, Shell, Raceway, and Pittstop. I use whatever is cheapest. Consumer Reports as well as government tests conclude that for most vehicles regular 87 octane is fine. I have never heard a ping on my 2006 G35 6sp manual. It runs just fine on regular. For those that feel better in using premium thats fine but I think its just a waste of money. We are all driving a depreciating piece of metal. Don't get me wrong, I love the G35 but in ten years I'll probably be driving something else?

Telcoman

Modern engines rarely ping on lower octane fuel. If you read up on it, or this thread you will know why.Might as well throw away the owner's manual, if you've read it. It does not know what it's talking about either if you want CR to be your guide. Show me where CR or the 'gov' says it's okay to run regular in a high performance engine. The breakpoint in compression rating is about 10:1. Much over that the engine will not be performing optimally. Besides a drop in hp at the wheel, fuel mileage can suffer, although not as much as the drop in power. The G35 has 10.3:1 and the newer G even higher. 10.6:1 I believe. The latest issue of Nissan Sport has a test run that showed a 10% drop in hp at the wheel with 87 octane fuel, and a 1mpg drop in mileage. And no pinging.Don't mean to beat you over the head with this info. I just don't think you are doing this car justice by running the same octane fuel as less powerful cars with lower compression engines.

Modified by ezflow at 6:15 PM 10/18/2006
Modified by ezflow at 7:10 PM 10/18/2006

[Q45tech]

Published static compression ratio means very little, as the important factor is dynamic running compression. [the cam specs set this dynamic condition].

The cylinder rarely gets 100% full at 14.7 psi atmospheric pressure due to restrictions in throttle position and intake valve flow ~~13.67 psi.

By definition the peak torque rpm at WOT is the rpm where the maximal filling occurs.............the amount of torque created per liter or cubic inch tells you the BMEP [brake mean effective pressure] exerted against piston.

Published HP @ some rpm and CR are just marketing terms to sell the aspect of engine performance to laybuyers.

In the 60 and 70's big blocks used high CR numbers with very radical cam timing [lopey bad idle smoothness] to reduce the 11-13 published CR to less than a real 10 CR to function even with leaded gasoline.

You really cannot rely on the pump stickers to tell you much about the gasoline they pump, other than it is good enough to function with the majority of engines and 3% will have problems on any day.

[ezflow]

An impressive display of knowledge, but to keep on target with the subject at hand for all readers, I stated, 10:1 in the practical world, is a guidline. The example given in Nissan Sport of an Nissan Murano V6 running 87 octane against 91 octane is a real world experience, not a theoretical one, but is certainly easier to generalize to one's experience with their own car.

I doubt there is that much marketing associated with compression ratios.GM runs most all their later model vehicles at 9.75:1, that is all the ones that they recommend running regular. A wise choice. And one I doubt is just a lucky guess. My own experience, as well as standards in the industry bear out that 10:1 is on the fence and probably most sensitive to different fuel grades. Naturally, other factors in engine design related to valve timing, as well as combustion chamber design, could throw things in one direction more than another.I have an Acura MDX with a premium fuel recommendation. The same basic engine in a Honda Pilot or Saturn Vue V6 has a regular fuel recommendation. Upon closer examination we find finite difference in valve timing, as well as ECU tuning to support each recommendation.CR is 10:1 for both engines.

An engineer's fuel recommendation is based on the most appropriate for maximum efficiency based on engine parameters (of which CR is a major one, always was, always will be) as well tuning. They could be off one or two octane levels either way, but part of the recommendation is also based on the variance the driver will encounter at the pump.Following the owner's manual recommendation is the safest and wisest choice, even in this less than perfect world.

[SVTCOBRA]

My 2003 Pathfinder would PING with Amoco 87 octane. So, I bumped it up to the middle grade. I do run Prem. in our G. Doesn't it say 'Premium Fuel Is Recommended for Maximum Performance' on the little gas door'??? Mine does. I likes Maximum Performance!!! Did I mention how I hate pinging!!! I might try the middle grade and see how it runs. I know from 'real world' experience that my 2003 Pathfinder (3.5L) didn't like the 87 octane flavor at all!!! It would PING!!! However, my 2001 Pathfinder (3.5L) didn't seem to mind the 87 octane....but, then again it's a 5 speed manual. That my be the difference. My 2003 was a 4 speed auto. Yep, I'm betting that you can get away with a lower grade with a manual.....course that's assuming you know when to shift...and when not to.

[ezflow]

Yep, I'm betting that you can get away with a lower grade with a manual.....course that's assuming you know when to shift...and when not to.

Maybe, but some folks can't get away with anything!

Seriously, the only problem bumping up the octane is not knowing how much is enough, but anything is preferable to excess pinging. And as stated quite eloquently by Q45Tech, there is a good amount of variability from station to station.So for that reason alone I go by the recommendation, which I believe offers enough padding for those unknown conditions.Butt Dynos suffer severely from any kind of accuracy. Only work for gross changes, usually too much or too little. The WOT argument is quite valid too.. this is where things generally become more obvious, and this can be proven with a scan of timing curves, and how much the ECU is really allowing the ignition to advance on different octane grades. Again, I'd rather just go by the book.I did my share of hand tuning on older cars. That's how we dealt with fuel variability in the land of Smog. Tweak timing for a slight amount of trace ping on hills, and we were good to go...

[BigWill]

Kind of like wine which vintage you buy:

Don't assume that the gasoline in the station tanks is necessarily made that day and every day by the same refinery. All gasoline is fungable and mixable as needed. When the tanker truck fills up a splash of marketing secret sauce is added to generic to make it the station label brand.

Sometimes the driver forgets or loses his eyedropper.

Bayway Refinery (ConocoPhillips), Linden, New Jersey 230,000 bpd Eagle Point Refinery (Sunoco), Westville, New Jersey 145,000 bpd Paulsboro Refinery (Valero), Paulsboro, New Jersey 160,000 bpd Perth Amboy Refinery (Chevron), Perth Amboy, New Jersey 80,000 bpd Port Reading Refinery (Hess), Port Reading, New Jersey 62,000 bpd

Marcus Hook Refinery (Sunoco), Marcus Hook, Pennsylvania 175,000 bpd Philadelphia Refinery (Sunoco), Philadelphia, Pennsylvania 335,000 bpd Trainer Refinery (ConocoPhillips), Trainer, Pennsylvania 185,000 bpd

I have to assume Q45, (although I know where that has gotten me before), that you are referring to bpd of crude processed. This is an area I know something about, as I work in the oil industry in So Cal. You are absolutely correct about the fungabilty of gasoline, as well as the products used to blend it. The same holds true for crude oil.

The company currently I work for stores, and pumps crude oil for all of the major refineries in the Los Angeles basin. We receive it from tankers in the harbor, as well as from gathering stations inland. The crude is only segregated by the properties having an effect on the refining process... API gravity, sulfur content, etc.

My previous job was in light oil products blending and shipping at a refinery, where we produced the raw materials used in the blending of gasoline, and sold them to various customers. Each petroleum refining company has basic standard methods for the production of gasoline, as well as proprietary and government regulated additives. Techron would be an example of a proprietary additive developed by Chevron. MTBE would be a government regulated additive. BP ARCO and Valero are two of the major players in the LA basin. BP ARCO alone processes 275,000 barrels of oil a day through the Carson California refinery.... but I digress.

The point is that the gasoline is produced by, sold to, and blended at numerous companies, no matter the location... Southern California, the Gulf states, the Northeast, etc. As a rule, the gas sold at the 'mom and pop' stations is a conglomerate of many refiners. Differences in the quality of the gas would have to do with many things, including the levels of water allowed, and the quality of the particulate filtering process... not to mention the condition of the pipelines, trucks and pumps at the stations.

There is no scam, or deception, (as I believe one person mentioned), regarding the octane of the product. Feel free to correct me if I am incorrect, but different engines are built to run more efficiently, or have more performance, on different levels of octane. The people who ignore the manufacturer's recommendations of what octane fuel is optimum for their vehicle's engine may never have a problem... most gasoline will make most any combustion engine designed to burn gas run, but incorrect octane for too long in a motor with high compression is not beneficial to the engine. The computer of a car might make allowances for knock, but why cause it to have to work to correct what could be corrected by simply using the recommended fuel?

OK... I have gone on long enough. All those in favor of an end to this post, raise your hands. (All those who believe in Psycho-kinesis, please raise MY hand.)

Thanks for listening.

[Q45tech]

One problem with blending gasoline from different refineries is you don't know how the mixture will come out octanewise..............it may be less, equal, or better than the simple sum of the two or three refinery products.

Octane is CALCULATED at the refinery based on component percentages.

The computer calculates what is expected with sum of all the components [historical actual measurements are averaged].

Brand new production gasoline degrades day by day as it goes thru pipeline and in storage at tank farms and in service station tanks from reactions with water and air.

Colonial pipeline:Speed: Moving about three to five miles an hour, a batch of petroleum to New York Harbor from Houston takes 18.5 days on average.

Plantation pipeline: Speed: One batch going to Washington National Airport from Baton Rogue takes 20 days on average.

Explorer Pipeline: Speed: One barrel of petroleum product going to Chicago from the Gulf Coast takes 11 days.

Living closer to the refineries has an upside if you are beyond the explosion zone.

Florida has NO PIPELINES AND is delivered by barges from Texas/ Louisana/MS

In Atlanta our gasoline from refineries to tank farm tanks is usually less than 7 days old and at high volume stations only last 3-4 days so worse case less than 14 days old in most vehicle tanks.

[BigWill]

One problem with blending gasoline from different refineries is you don't know how the mixture will come out octanewise..............it may be less, equal, or better than the simple sum of the two or three refinery products.

Octane is CALCULATED at the refinery based on component percentages.

The computer calculates what is expected with sum of all the components [historical actual measurements are averaged].

Brand new production gasoline degrades day by day as it goes thru pipeline and in storage at tank farms and in service station tanks from reactions with water and air.

Colonial pipeline:Speed: Moving about three to five miles an hour, a batch of petroleum to New York Harbor from Houston takes 18.5 days on average.

Plantation pipeline: Speed: One batch going to Washington National Airport from Baton Rogue takes 20 days on average.

Explorer Pipeline: Speed: One barrel of petroleum product going to Chicago from the Gulf Coast takes 11 days.

Living closer to the refineries has an upside if you are beyond the explosion zone.

Florida has NO PIPELINES AND is delivered by barges from Texas/ Louisana/MS

In Atlanta our gasoline from refineries to tank farm tanks is usually less than 7 days old and at high volume stations only last 3-4 days so worse case less than 14 days old in most vehicle tanks.

I have to say, Q... if you are nothing else, you definitely are thorough!

(Not hatin', just observin')

[Q45tech]

Remember gasoline is a mixture of 200+ chemicals some in small less than 1% quantities.

Every base oil from every different well in the world contains differing amounts of these chemicals. Oil coming off a giant tanker is not homogenous..............oil feeding the refinery is not homogenous so the percentages per input barrel vs individual fraction column outputs are not equal minute to minute much less hour to hour.

When you have known amounts easy to blend to a formula, HOWEVER what do you do when you run low of one key ingredent? You don't stop running you just change the mix within some range to keep producing gasoline.

Hoping that the 50,000 or 500,000 gallons will fix itself when combined.

The automatic blending is done by computers [watched by programmers] to avoid getting too far off course. The output stream is monitored [sampled with IR Spectrography] to make sure KEY ingredents are close.

[The_Scooch]

This is all really great info and even better conversation. I've been racing and testing various fuels for 15+ years. I could get into specifics but for me it comes down to this...

When it comes to consumer pump gas, my car runs awesome on Chevron or Texaco and runs like absolute crap with Shell. I don't know what they did to it with that "V-Power" junk but it's all screwed up now. In fact, my last car would set off the check engine light if I ran Shell within a half tank. Yes, I tried different stations. My bike also runs like crap with Shell. All my cars and bikes are hi-comp and I only use high octane gas.

[ezflow]

I don't have the link handy, but there is an article from a petroleum engineer on gasoline additives.In a nutshell, different compounds are used in detergents depending on the company. They are similar but some are more effective for cleaning up specific types of contamination more thoroughly than others.His conclusion is that it is beneficial to change brands (if you typically run only one) for a few weeks at a time. Interesting theory anyway.

[john001]

VALERO IS ONE OF OUT CLIENTS.

FROM THE VALERO WEB SITE:

Valero Energy Corporation is a Fortune 500 company based in San Antonio with approximately 22,000 employees and assets valued at $33 billion.The largest refiner in North America, Valero has an extensive refining system with a throughput capacity of approximately 3.3 million barrels per day. The company's geographically diverse refining network stretches from Canada to the U.S. Gulf Coast and West Coast to the Caribbean.

A marketing leader, Valero has more than 5,000 retail and branded wholesale outlets in the United States, Canada and the Caribbean under various brand names including Valero, Diamond Shamrock, Shamrock, Ultramar, and Beacon. The company markets on a retail and wholesale basis through a bulk and rack marketing network in 42 U.S. states, Canada, Latin America and the Caribbean

[PGrated]

I have found that I have had trouble with gas from one particular Mobil station and not from another Mobil station just down the street. My old Pathfinder was very sensitive to it. I'm not sure what was the difference between the two...but there definitely was a difference in performance of the car.

Anyway, just an observation.

pgrated

[Q45tech]

Since premium costs the service station about 6-8 cents more [they sell for 20-25cents more] than regular, many states check once every few years to see if the station might be selling regular as premium. Primarily all the states look for is accuracy on the pump vs delivered amount [1 gallon = 1 gallon]

A great time to switch would be just after you got your annual test done.This requires collusion with the tanker truck driver to dump a load of regular in the premium tank.

Like magic you can make [pocket] 6-8 cents more per premium gallon sold.....you must buy some premium or you will get caught [sales tax vs purchase records] but if you mix ~~50/50 and reduce the premium to mid grade who will know. You can post a perceived discount on your [special diluted] premium to attract customers....................a win win except for those cars that actually need a REAL PREMIUM!

Premium sales are 20%. midgrade [supposedly a 50/50 blend from the two tanks] is 10% and regular is 70%.

Say 20,000 gallons out of 100k per month yields an extra 8 cents, $1,600 more in your pocket less the driver bribe. Plus the 4 cents extra on the midgrade is another $400.

Not saying it's common just watch out for the ocassional symptom!

If caught [almost impossible] the driver is to blame for mixing up the filling process.

[redhed]

i really wish folks would quit using the term premium when it comes to gasoline. it should be called what it really is...high octane. the oil companies penned the name premium as a ploy to get people, who don't need it, to buy more expensive fuel!

call it what it really is...low, mid and high octane!

[C-Kwik]

semantics....

[yelnatsch517]

Here in Central New Jersey I see the same Island Transportation Tanker Trucks at many different branded stations. Even Hess which used to have their own trucks now have Island Transportation trucks filling their tanks.Our reg gas prices fell to $1.98 gal today. Within 2 miles of where I live, I have BP, Hess, Lukoil, Shell, Raceway, and Pittstop. I use whatever is cheapest. Consumer Reports as well as government tests conclude that for most vehicles regular 87 octane is fine. I have never heard a ping on my 2006 G35 6sp manual. It runs just fine on regular. For those that feel better in using premium thats fine but I think its just a waste of money. We are all driving a depreciating piece of metal. Don't get me wrong, I love the G35 but in ten years I'll probably be driving something else?

Telcoman

It's just simple physics as to why higher octane fuel runs better than lower octane fuel for higher compression cars. It is your car so it is ultimately up to you. Basically, the higher the octane, the harder it is for the fuel to detonate. Using lower octane might result in pre-detonation and loss in power, engine degradation, etc. Most newer cars can detect this and compensate, but still.

It's not whether higher octane is "better" for your car as you seem to think. It is what the engine is designed to use. By your logic, a turboed car would get the same benefit out of 87 and 103 octane.

You don't feel a power difference because a.) you never took your car to a dyno and b.) from what you posted, your personality basically shows you are a very passive driver. If you drive your car like a grandma it is obvious you won't notice a difference.

By that logic, you are saying a piece of paper is as strong as a 1/4" MDF board because a round from a 50 caliber rifle blows through both with equal ease.

[ezflow]

Most newer cars can detect this and compensate, but still.

That is the key right there.

For that reason some folks will not run premium, because regular or midgrade 'causes no problems'.

They are either ignorant of the fact the engine will not be running as efficiently or simply ignore the fact.

The documented (Nissan Sport, lastest issue) test performed on a 2003 Murano with both 87 octane vs. 91 was quite dramatic. 10% loss of WHP is not a small thing. Mileage was down by 1mpg.