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Best Fuel

16K views 31 replies 20 participants last post by  MarkYorks 
#1 ·
Hi

I’m less than a week into Porsche ownership. 718S Boxster. Loving it.
She’s due a full tank of fuel tomorrow. What are the recommendations for fuel? The car has done about 25,000 miles. I am a previous F Type owner who ran into multiple problems with injectors. Not sure if that was fuel related or car related.
Thoughts? I live between two Shell garages. Do I go standard or VPower?
Bw J
 
#5 ·
In my opinion, any main stream Porsche sold for street use, unless otherwise specified with some special mod or model, will only require minimum 93 Octane. It appears to me 93 is the highest common Octane in the US although I have seen some rare gas stations with higher. My 2019 Base Boxster specifies, Octane Min (RON+MON)/2=93.

So, can I assume, no matter what load (within the red line) I place on it, if I use minimum 93 octane, it will not detonate and supposedly will not require any spark retardation and associated power reduction under high load? I think this is the case and I have never seen anything stating otherwise.

If so, anything higher than 93 octane is a complete and total waste of money and accomplishes nothing. The ONLY purpose for being concerned about "Octane" is to prevent destructive detonation. There is absolutely ZERO power advantage of using a higher octane recommended by the manufacturer. Octane has no consequential relationship with energy content, it only effects how the gasoline vapor behaves when exposed to a spark (burn or explode).

I have understood in not too many past years higher octane (more expensive) gasoline had better detergent packages added and therefore, with respect to maintaining valves etc. it had an advantage. I have read a number of time in the past ten (maybe twenty) years or so that the difference in detergent packages no longer is consequential and there are now governmental regulations driving the minimum detergent package.

In WWII USAAF and RAF aircraft had a significant power advantage over other countries aircraft because a conscious decision was made to manufacturer high octane av gas (115-145 I think) in the late 1930s. The additional engine power did not come from the higher octane but the high octane did allow the engine manufacturers to build higher compression engines that could operate at higher power levels. I think a myth probably developed from this history that feeding a given engine high octane gas means it will produce higher power than with lower octane. In 1965 I had a summer job pumping gas. All the taxi drivers requested half regular gas and half premium and all believed their taxis had more power when they did this.

In 1988 I bought a new BMW E30 M3 and started dating a wonderful woman that soon became my wife. The M3 required minimum 91 octane. One day Kathy was driving the M3 and needed to fill up. I told her "Premium" gas was required. Knowing my analness about verbatim compliance with a manufacturers requirements, she filled the car with "Premium" gas. Unfortunately, in 1989 there was "Regular 87 octane", "Premium 89 octane", and "Super Premium 91 octane". I called BMWUSA to ask if any problem driving with a light foot as I now had a full tank of 89 octane gas. They very firmly told me to have the car towed to a shop and the tank drained. Since I was still well in the warranty period I did drain the tank but I did not tow it the 35 miles to the shop. We still got married a few months later and had good laughs about it for many years, most, unfairly, at my expense.
 
#7 ·
I got my Cayman about 3 months ago (had done 18k miles). First fill up I put standard fuel in (95)... It was only after I started reading around forums I found I wasn't supposed to... sincey I have filled it up with 99 at Tesco. This is a big Tesco, but strangely all the other petrol stations around dont go up to 99.

Placebo or not, the car felt punchier with 99!
 
#8 ·
I am convinced Top Tier brands is more marketing hype than anything consequential. I can only speak from my own very limited experience but I have mostly used Racetrac and more recently WaWa (niether apparently Top Tier) for at least 20+ years in a multitude of vehicles from Lexus SUVs/hybrids to BMW Z3/Z4s/X3s etc. In most cases these cars have near or over 100K miles when I replace them and my 2002 Z3 had almost 170K. I dont have any particular reason for using these brands other than they are typically much more convenient, do not have the cash/credit price delta, are a lot cheaper, and mostly maintained in excellent material/clean condition. I have never had a single indication of a problem. Additionally, I have heard it said a number of times from magazine articles to private shops I trust that the minimum government requirements now for additive packages are more than sufficient to prevent carbon buildup on valves etc. This was not at all the case back in eighties (and maybe later) when it was not uncommon to see a late model BMW having its valves cleaned with crushed walnut shells. I suspect this is still done but it does not at all appear to common as it was then. Porsche recommends minimum 93 Octane and I sleep well at night feeding it that from any main stream well maintained (at least in appearance) gas station.
 
#9 ·
Hi

I’m less than a week into Porsche ownership. 718S Boxster. Loving it.
She’s due a full tank of fuel tomorrow. What are the recommendations for fuel? The car has done about 25,000 miles. I am a previous F Type owner who ran into multiple problems with injectors. Not sure if that was fuel related or car related.
Thoughts? I live between two Shell garages. Do I go standard or VPower?
Bw J
Hello!

Your car is supposed to run on “Premium” fuel and if you check the manual you’ll see that for the UK you should be using 97/98 RON (also crucially there is a difference between UK and US octane ratings), which means v-Power if you’re at a Shell garage.

There’s a fair contingent of UK drivers on this forum and the consensus seems to be that whilst v-power is optimal, good results can be had with Tesco Momentum 99 as well. I personally use v-Power or Esso Synergy (used to be 97, now the Supreme is 99).

The car will run on “bog standard” 95 RON fuel if you really need to however it is not recommended and anything lower - the car is smart enough to know and change ECU settings to compensate, just don’t do it too often and don’t run it on anything less. Also try to avoid fuels with more than 5% ethanol (E5) as it saps power. E10 only if no other alternatives. These are not just my opinion, that’s straight from Porsche.
 
#11 ·
Just a plug for top tier fuel, years ago I had a Toyota Tercel and I had a fondness for Chevron premium gas. Everyone said I was nuts to spend more than I needed, particularly on what was at the time Toyota's cheapest car. I had a great mechanic in St. Pete, FL, that I used and he threw his used parts in 55 gallon drums. Whenever hanging out in his garage waiting for my car, I'd look in the drums to see if there was anything interesting to note. There were always dozens of the transparent gas filters that were badly clogged in the barrels. I asked him about it, and if I needed to change mine yet. He just muttered "cheap fuel" and "no". At 125,000 miles, I had a CV joint going out and I demanded, while he had the engine and trans-axle separated anyway, that he change my original clutch (another story). When I came to pick my car up, he dragged me over to one of his 55 gallon barrels, pulled out my clutch pad and said "This has another 24,000 miles on it!" There were the usual flotella of gummed up gas filters in there also. So I asked him if he had checked my original fuel filter and did it need changing, to which he said, "Yes. And No!"
 
#12 ·
I have a friend that heads trucking division for a bulk-fuel delivery company. They deliver fuel to many of the major gas stations and some independents. They get all of their fuel from the same bulk fuel distribution center. The only difference is in the formulation of additives each customer stipulates. He tells me there is essentially very little difference between fuels among gas stations and the only caution he has is in making sure he goes to a highly visited station to avoid stale gas which could be an issue with premium graded fuels at less frequented stores. He buys premium fuel for his C7 at a local independent station most times.
 
#15 ·
What he said! +1.

I used to work for a major oil company. Our refining guys told me that no fuel leaves the refinery if it is out of spec. Regardless whether it is to be delivered to a company owned or franchised gas station, or an independent. However, for the company brand stations they added the proprietary company additives. They are different from company to company and can make a difference.

Now the cleanliness standards may be different for a company owned station (very few left), a franchisee or an indie.

I remember talking to a BP franchisee in faraway Greece. I was complaining that I had to pay a substantial amount of money to change the float sensors in my Mercedes, traced to a local gas station near the worksite I was frequenting with a friend that supervised it there. They had the cheapest prices anywhere in Greece and was a (Greek oil) company station. The BP guy walked into the office and produced reams of automatic testing for his tank filters, saying the equivalent of 'you can pay me now, or you can pay Mercedes later...' :eek:
 
#14 ·
95 RON fuel is pants. I ran a tank of it when deciding what fuel to put in (and it was Shell 95).The car just doesn't like it. I run mine on Tesco Momentum and the car loves it. Pick up is superb and power delivery linear, plus its cheaper that V-Power. I do put a tank of V-Poer in though every once in a while.

Porsche Club GB members get 5ppl off Esso Synergy fuels if you have the fuel card.
 
#16 ·
@MLJJ has it right: gas is, for the most part, gas. It's the additive package that really differentiates the brands, the quality of the retail facility that ensures the gas stays clean and free of water, and the freshness of the gas. Here in the US, Mobil and Shell have the best additive packages. "Top Tier" is a great marketing effort. If you have a port injection engine, just buy the least expensive gas from a busy gas station. If you have direct injection, stick with Mobil or Shell as they have the best (but still not great) additives for dealing with carbon buildup on the intake valves.
 
#17 ·
well if you say gas is gas but make distinctions and recommendations then gas is "really" not all the same. I agree it is the additives that make them different and possibly beneficial .

For those old enough to remember the commercial, "motor oil is motor oil", LOL
 
#22 ·
I think quality storage is an important aspect and I think now that is probably easier with the type of underground tanks that being used. I suspect that contributed to my experience 30 years ago that I described above. My question is, if premium gas is more finely refined as part of the process wouldn't that net better filtration of solids?
 
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#23 ·
Hi

I’m less than a week into Porsche ownership. 718S Boxster. Loving it.
She’s due a full tank of fuel tomorrow. What are the recommendations for fuel? The car has done about 25,000 miles. I am a previous F Type owner who ran into multiple problems with injectors. Not sure if that was fuel related or car related.
Thoughts? I live between two Shell garages. Do I go standard or VPower?
Bw J
The only gas I put in my 718 is Shell V-Power and it runs fine
 
#24 ·
Shell really does a great job marketing. Seems that many people really buy into them being the “best” gas.

I think anything top tier is fine but in a pinch I wouldn’t hesitate to put in an off brand. In all my years of driving I have never experienced any gasoline related car issues.
 
#28 ·
I wouldn't say Shell gas is just a matter of great marketing. With my previous 2 cars, both of which had their ECU re-tuned, the engine definitely ran the happiest with Shell V-Power, followed by Chevron Ultra 94. Esso / Mobil are both Tier 1 gas as well, but both cars hated Esso / Mobil gas. The engine runs more coarse, it is less happy to rev, and it feels like the ECU is pulling timing. And this occurs consistently whenever I refill the car with Esso / Mobil gas.

Now, in a mass market car with the normal mass market factory ECU tune, perhaps it won't matter. But in something that is more finely tuned, the gas you put into it will make a difference.
 
#25 ·
I put Costco premium 92 octane in My BMW 535 series and it runs fine but if I put Shell V-power in it seems to be a little more responsive I would not put Costco premium in my 718 though Not in that high performance motor The funny thing is I have never seen a high performance car at a Costco station
 
#27 ·
In Germany we have Aral Ultimate 102 Ron, i compared it several times with standard premium 98 Ron and in my opinion it´s worth the extra money, i feel more punch and better throttle respond - special in hot summer days. So this is my fuel tune ;)
With 98 Ron the tailpipes always where blackened with soot - after 500km with Ultimate 102 they are clean.
 
#30 ·
Top Tier gas is actually the real deal. As car engines moved to direct injection, it became necessary to have an "upgraded" detergent package to keep the valves "clean". Before direct injection in cars, port injection would flush the tops of the valves with the fuel/air mixture on the way to the combustion chamber. That is why Honda has a combination of port injection and direct injection in some (all?) of their engines. When I originally heard of Top Tier, I did some research. The first pages showed all the vague marketing language: Blah, blah, blah. Then I hit the page going into the laboratory additive formulas, results measurements, etc. Although I have an engineering degree, I was immediately over my head. What I did discover is how Top Tier was funded and how it would be applied in the field. Four major car companies put millions of dollars into the project. My memory is that the original big 4 were GM, BMW, Toyota, and VW. They not only helped develop the fuel additives that would accomplish what they needed for their new engines, but they also set up a periodic testing system for every gas station nationwide where those particular stations sold Top Tier branded gas. This insured that you got the right additives, primarily for the newer direct injection engines, at any branded station you might visit, whether it happened to be in New Jersey or Nevada. Initially there were only about 5 brands that were committed to Top Tier, Chevron and Shell were 2 of them -- but other major brands such as Mobil were not yet involved. Consumer Reports published a detailed article on Top Tier and started off the article with the question, "Is Top Tier worth the money?" Their answer, before even explaining why, was "Yes." In our Tucson area, Speedway recently bought up a large number of stations, most of which sold Top Tier. There was a large article in our local paper about this corporate purchase, about the stated policy of Speedway to NOT offer Top Tier gas, and about the numerous mechanics in town who were strongly advising their clients (some of whom had already had engine rebuilds for not using Top Tier) to NOT use Speedway. I have found nothing anywhere that says Top Tier is just marketing hype. Remember, the whole effort was started by car companies, not petroleum companies.
 
#31 ·
I live in Alaska and the highest octane gas we have available is 90 weather it’s shell, Costco, chevron etc.. I’d really like to do a Apr tune on the Gts I’m purchasing but see that they want 93 when tuned. Apr suggests not using any sort of ocatne boost. Any advice on what I might be able to do and still keep the tune safe?
 
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