A "Shell" of a note!
 

I have almost exclusively used Amoco/BP gasolines in my cars for years until recently when I decided to "test" the Shell advertizement on TV claiming increased fuel mileage. I have carefully noted my fuel mileage for the last two years using Amoco/BP and was getting 17-18 mpg in urban driving and 25-26 mpg on the interstate. This equated to approx. 300 miles per fillup in town (leaving 2 /12 gals in reserve). With Shell 93 octane I now seem to be getting about 350 miles per tank with the same reserve. If I did the math correctly, that amounts to an increase of 16-17%! This increase has been consistant thru 5-6 tanks of fuel. I would like to see someone else give this a try and report back on their results.

Thanks,

Fred Cook
'80 911SC coupe SmileWavy

I think the only guy around here that really*knows* gasoline is 'sammyg2'.
Maybe he'll comment.....

I built gas stations for 10 years (all brands) & will only use Chevron in my Pcar. Their standards were well above everybody else.

Hey Paul,
A convenience mart called "Giant, Conoco" was built in 2000 on the corner about 1/4 mile from my house. Chevron bought it about 3 months ago. When you speak of standards, to what are you referring? Teach me. I always wonder about that stuff.

My dad swore by Sunoco for years. I had good luck with Shell. Was I full of it or is there a real difference? I always hear folks refer to fuel as "That swill they call gas!" and wonder just how different it can be.

I don't know about the mileage thing, but my dad retired from the Shell refinery a couple years ago. He said if Shell says it's 93 octance, it's definitely 93 octane, and maybe better.

The way I drive the 911 indicates that mpg is not at the top of my priorities.

Don, when ever we did any work for Chevron, whether a retrofit or new construction, their primary concern was qaulity of work & materials. I can not say this about the others. With the exception of Texaco all others were primarly concerned with saving money & time, Arco being the worse. When things would get slow at work usaully during the rainy season I would go around & pump water out of the bottom of service station storage tank because of ground water migration. A couple of times I would pull up to a station & there would be a line of stranded cars down the street from pumping water. :eek: . Don't recall pumping any water out of Chevron tanks. I don't know jack about the gas before it is delivered to the station, but the tanker drivers told me it's all about the same with the exception of which additives are used. I have been out of that field for 5 years now, but I doubt things could have changed much.

I grew up with the impression, from the old school hot rod builders, that Shell oxidized the engine internals more than other brands.

I've been a Mobil fan for many years. However, I believe most high line brands are pretty comparable....but not "from the same storage tank". Low line brands tend to have higher sulfur content and less sophisticated additive packages.

I got a giggle out of one of Shell's marketing signs last time I filled up there:

"Shell gas is proven to reduce internal engine friction in standard EPA tests"

HTF does gasoline reduce internal engine friction?

I've been using Shell because there isn't a Chevron conveniently located near me, and the Shell is right on the corner as I leave the office.

That being said, I'd swear my 911 runs better on Chevron; the VW bus doesn't seem to care.

Thom,

Same here with a recent motor oil ad I saw.

Their big claim was, and I quote directly, "XXX motor oil reduces friction in your engine!"

NO KIDDING? An oil that REDUCES friction? My stars what a world we live in.

One of the most important factors you should consider when choosing a brand of gasoline is the company name and logo. It's a matter of word association, really. Here's the breakdown:

Shell: Specifically seashell, according to the logo. So typically, when you see Shell, you think of the seashore... a fine area for a leisurely drive. Shell gets my vote.

Mobil: Mobile, misspelled; part of automobile. My automobile obviously needs Mobil to run. Vote yay.

Exxon: Sounds like ex-con. Although disguised in a red, white and blue logo, this brand should not be trusted. Look what the tiger did to Roy! Heck no to Exxon.

76: A very good year... plus the orange circle is cute. It gets my vote.

Texaco: The company of Texas. I had way too much Bud Light in Amarillo that night. Bad experience, bad gas. Say no to Texaco.

Amaco: As in, "I Am a Company." Too egotistical. No thanks, sir.

Chevron: Makes your Chevy run... which is often quite a difficult task. Plus, they rate themselves with two whole stripes. That's twice as much as one so they must be good!

Actually, I primarily use Chevron in the West and Mobil in the East. I've got bi-coastal disorder. Mobil was the only fuel that cured my old Ford's hiccups, and Chevron is always readily available out here.

Wouldn't mind if there were Chevron stations around these parts. It'd be nice to get that dose of Techron with each fill.

Up in N. Cal. we have Valero, to include to the list,which I think bought out BP. The Worst gas ever!!
had to fill up at one of the stations once and for the rest of my fun drive up the coast my car knocked on the steep inclines.
I had never had that problem before.
It was the 91 octane too.

around here Chevron is unusable..has the highest allowable ethanol content which has destroyed multiple fuel system components!

I had used Sunoco 94 for years, it was close to home. Now Mobil is close, Pcar don't seem like Mobil, I to wish we had Chevron around here. I've taken to believing that its better to buy gas from a high volume station as there's a better chance the higher octane is getting cycled more. I still run Sunoco 94 in the 964, but from a different station which is further away but much higher volume, So what if it takes 20 minutes to get to? It's all about the driving........

Sunoco. When I owned my first car, an MG, it drank Sunoco 260 exclusively. Nowadays, my 993 likes the Ultra, and the E runs just fine on regular. Unfortunately, we don't have nearly enough Sunoco stations here in NoVA.

I have seen a gas mileage improvement in my two vehicles when run on shell, with the more noticable being in the p-car.

HOWEVER, these aren't really all that scientific as far as testing is concerned, different roads and different atmospheric conditions, etc. Overall, over the course of the last few months, I have noticed better MPG with Shell than with other brands.

The reduction of engine friction makes sense to me, with the detergents/deposits on cylinder walls helping to lube the ring contact area. It sounds like an additional benefit to me unless those 'lubricants' build up over time.

For what it's worth if they were all lined up on the same corner I'd choose Chevron over Shell...

Interesting thread though!

When that Shell adsvertisement hit I also said WTF?
I started asking around in the industry and most of the folks who should know all had the same story:
Shell came up with a detergent package that was a little better than before, not much just a little. In controlled labratory tests it reduced engine friction slightly by cleaning some of the deposits off of the parts exposed to combustion.
It wasn't a big deal until the advertising types got a hold of it.

I haven't read the test results (haven't been able to find them yet) but the experts I talked to who expressed an opinion suggested that the improvement (if any) would be so small that it would not be measureable in real life.
Even Shell's own website lists the improvement as 1% (optomistic?) but does not say what they are comparing it to. Their official article says that a driver should expect to save 125 miles worth of gas a year, provided they drive 12,500 miles per year.
It may be that it is 1% better than the previous Shell gasoline, I won't know until I get a hold of the actual test results.

IMO an improvement of 16 to 17% is due to some other factor and not the gasoline. Have you tried alternating fuels to compare?

Ambient temperature and the time of the season could also comes into play, gasoline is blended differently in the summer than in the winter for RVP compliance.
Higher air pressure in your tires in hotter months will make more mileage difference than this gas will.

We have a huge amount of mobil stations around here. I try to avoid them. Sunoco seems to be the best. I do know that in any of our cars we get better milage with shell. The mobil runs right thru all of them. I can pick up anywhere from 15-60 miles a tank depending on the car using sunoco gas.

Got Gas?
 

Actually, I agree with SammyG2. It seems unlikely that an additive package could make that much difference in fuel mileage. And it may be that I have been subconsciencely driving differently after changing to Shell. One thing that I have noticed and am certain of, is that my car idles better and runs "smoother" on the Shell 93 octane. The (unexpected) results that I seemed to be getting is what prompted me to post the above poll. I knew that if anyone else on this board had tried different fuels they would chime in with their experiences.

Thanks,

Fred Cook
'80 911SC coupe

Re: A "Shell" of a note!
 

I used to use Amoco, but when they were bought by BP, the price of their premium went up. I don't buy Mobil/Exxon, since their Chairman of the Board made a big deal out of saying that greenhouse gases are a figment of environmentalist's imagination, and they stopped doing research on gas efficiency and pollutants. As a result, really, their sales dropped, and they now sell their gas for typically 1 - 2 cents a gal cheaper than the other majors in Chicago.

I got a kick out of the subtle Shell campaign, and started switching back and forth between Shell and Amoco, just to see if I could document a difference in the mileage - I track my mileage on my Palm using a program called Autobase. I found that the Shell gave me consistently better mileage, but it was closer to 5% than 16%. To be totally honest, my driving habits made a bigger difference than the gasoline choice. I have always heard that the choice of brand for gasoline or oil is less relevant than your personal feelings. The majors all do it the same. It all comes out of the same ground.

In Illinois, there is a mandated 10% addition of Ethanol to EVERY gallon of gas. And I thought that the early cars were supposed to run on regular. Does everyone use premium?

BTW, Wong, that was as good a way of choosing as any. Loved the analysis.

larry

Richard, that's the first time I've heard about a problem with Valero gasoline. I run it in my truck all the time (unleaded regular) without problems at all, but my truck does not like Arco gas.

I know that Valero is in the process of switching to methanol mixed gasoline and fazing out MTBE, I wonder if that has anything to do with it.

Supposedly all gasoline is the same and only the additives are different, but that is not always true.
Basically that is correct but different refining processes product slight variations of basoline blends.
Straight run gasoline is almost always the base stock and it is blended with high octane ($$$) stocks to achieve the desired component. These high octane blend stocks are created in process units that modify the hydrocarbon molecules and are not all the same.
Types of these processes are:

reforming, where a catalyst and hydrogen are used to change the organization of the molecule (usually a platinum catalyst, very expensive) but these reformed molecules can be unstable and break down over time.

Calalytic cracking, where heat and catalyst actually break a long chain molecule like a heavy oil to smaller molecules like gasoline, (also unstable over time but not to the same extent)

or Alkylate catalytic processing where acid (either hydrofluoric or sulfuric) is used as a catalyst to mix iso-butane and naptha based molecules to make a very desirable stock.

Most refineries have very similar processes designed and licenced by either Philips, Unocal or UOP etc, but the majors have enough money to design their own versions of process units and avoid paying licencing fees.

The different processes can create a slightly different type of blend which work better in some cars and worse in others.

Here's the tricky part, just because a gasoline is sold at a mobil or sunoco or chevron or valero station does not mean it is refined by that company.
Sometimes it is, often it is not.
Gasoline is traded openly between refining companies to meet commitments so you never know who's gasoline you are getting. Sometimes a gas will not work as good, and then the next tankful from the same pump will be better. The only thing that is supposed to remain constant is the type and concentration of the additive package and the octane rating that you get from a certain brand.

So sammy, I don't know if you've mentioned it before, but what do you run in your SC?

I've never really noticed a difference between brands, but then I've never really paid attention too closely either. I usually use 76, because there is one right by my place, and they advertise no MTBE.

All this talk has me curious, and I want to try something else for my next few tanks. Probably chevron, I think.

Dan :)

I work for BP, think this is refered to as AMOCO in the US.

Within the fuels industry there is so much inter trading and swapping of fuels, you could be getting any brand of fuel from any brand of station so unless your getting somthing Like shell optimax its all much of a muchness.

When I first got the SC I was running premium, either Unocal or Shell. After a couple tanks I went down to the mid grade (89 octane), no difference.
I have chevron regular unleaded in it now (87 octane, trying to pass smog) and I still don't detect and difference but I have it leaned out a bunch so I won't know for certain until I put everything the way it should be.
BTW, MTBE is not a bad thing unless you are concerned with the alleged environmental problems.
The gasoline that used to contain MTBE in California is being replaced with gas that has as much ethanol as they can blend in. If I had a choice I would like to run gas without either additive, but I'd pick MTBE over ethanol any day.

I've tried many brands over the years and the only time I've ever noticed a difference was with ARCO gas and that was only with a turbocharged 2 liter 914. It did not like Arco premium at all.

I do tend to avoid off brand stations. One other thing I do is to always try to go to a busy station. I don't want to buy gasoline that has been sitting in an underground tank for a couple of months.

Thanks. A friend of mine is a hydrologist (I think that's right -- does the whole groundwater thing) and she studied the effects of MTBE in one of her classes. She said it wasn't so great, and I believe her, so... Basically just a 'might as well' decision.

Dan :)

You guys just like Sunoco (Sun Oil Co.) 'cause it was the primary sponsor on Penske's 917/30 :D . They don't retail on the left half of the USA; wish they did.

Have to try the Shell test. The Phillips 66 seems to be pretty good, and the LCD graphic display on the pumps have a 911 on them :p .

Well, for those who live in this area, there's a Shell station on Franconia Rd. and the owner has a gorgeous zenith blue 993 C2S. He's a great guy and will always stop to talk to the Porsche drivers that pulll up, offer to read your fault codes for free, offer his lift for DIY work, etc.

MTBE is a bad thing when it gets into the ground water. No one would argue about that.
My problem with those who are so much against it, are they saying that MTBE is bad for ground water but gasoline isn't?

I say the real problem isn't the MTBE, the real problem is that gasoline and the stuff that is added to it is leaking into the ground and that is what needs to be addressed.
Banning MTBE will not solve the problem. It will only add to the price of gasoline and reduce the available production a little.

I look at their efforts as a band aid, attack a symptom and not the diesease.
Thier intentions are probably good but they are misguided.