Anyone use 93 octane (premium) fuel on the 3.5?

[AntDeek]

On most Ford promotional material for the 2013 3.5 TI-VCT, it states fuel economy is tested using 93 octane. Any difference in MPG or power?

[chefduane]

2013 calls for 93? Spec for 2011 3.5L is 87.

[WWWPerfA_ZN0W]

There will be some improvement as factory tuning accommodates 87-93 fuel. Not as much as a custom aftermarket tune, but noticeable. Ethanol free fuel will meet you even more gains.

[ben senise]

where do you have 93 octane? i go to SoCal once in a while and i've only seen 87, 89, 91 like we have here in the west coast of canada. i have seen 100 octane at one place where the guy i was driving with filled up his Carrera GT.

 

i never did any testing with my '09 3.5 but I have with my '16 3.5.

i get about 10% better mileage with 89 and than with 87. No further improvement with 91 over 89 so i use 89.

Mileage is around 5% better in the summer than in the winter. I don't know if this is due to different fuel mixtures, due to the fact that i use the seat and steering wheel heaters, or just the fact that the weather is colder.

i would say that the torque feels higher with 89 over 87 but that's a subjective observation, not empirical testing. Likely influenced by knowing what's in the tank.

 

[edit to correct typo]

Edited January 1, 2018 by ben senise

[AntDeek]

Gotcha. My manual does say 87 octane but all promotional material states MPG is tested on 93 octane.

 

Here in NJ we can get 93 any day.

[akirby]

In GA we have 87, 89 and 93. 91 is common on the West Coast and in higher elevations.

[ben senise]

funnily enough, i just found out that Petro Canada offers 94 octane in Alberta and Ontario.

 

it was an ad served up on a web page. coincidental? i think not. big brother is watching.

Edited January 1, 2018 by ben senise

[lildisco]

Clear your browsing history/cookies or browse incognito.

[ben senise]

Clear your browsing history/cookies or browse incognito.

Thanks. I'm familiar with the tech. I don't care about the targeted advertising. I was trying, unsuccessfully I suppose, to be funny.

[TheWizard]

The recent Cyclone Ti-VCT V6 engines (3.5L and 3.7L) are designed to advance ignition timing to improve performance when higher octane fuel is detected by the knock sensors. The gain in horsepower is measurable but fairly small and occurs at high RPM so most drivers would never notice it. The gain in mileage is also small but can amount to as much as 1 mpg... a significant amount for marketing and meeting federal CAFE standards. The problem is that the mileage gain doesn't come close to covering the extra cost of 93 octane over 87 octane. You may gain a little mileage but still end up paying more for gas overall (fewer gallons but more dollars).

 

As mentioned, ethanol free fuel will give you even more performance gains - enough to actually feel with the seat-of-the-pants meter but again at considerable extra cost. Here in Florida, pure gas costs about the same as 93 octane E10 (which is 50-60 cents per gallon more than 87 octane) and is commonly rated 89 octane but still gives more noticeable performance improvement. It's up to you whether it's worth the extra money.

[akirby]

The recent Cyclone Ti-VCT V6 engines (3.5L and 3.7L) are designed to advance ignition timing to improve performance when higher octane fuel is detected by the knock sensors.

 

Not to be a stickler but that isn't quite accurate. The knock sensors don't actually detect higher octane fuel. The PCM advances the timing until it starts to knock then retards the timing slightly. With Premium it can advance the timing a lot further before knocking occurs.

[TheWizard]

That's correct... I didn't go into enough detail in my description.

[akirby]

That's correct... I didn't go into enough detail in my description.

 

I figured you knew that but wanted to make sure others didn't misinterpret it.

[MaX83_ZA]

I am a firm believer of driving only premium fuel in performance turbocharged cars. Have a look at these tests for interest sake.

 

http://newsroom.aaa.com/wp-content/uploads/2017/12/Premium-Fuel-Phase-II-Research-Report-FINAL-2.pdf

[TheWizard]

That report adds interesting detail and confirms what has been discussed... if the manufacturer says the vehicle requires high octane then always use it and if it says high octane recommended then the choice is yours - spend the extra money for a minimal increase in performance/mileage or save the money. If 87 octane is specified then most cars gain absolutely nothing by running higher octane. We ran our Ecoboost Edge on 87 octane all the time after trying both ways and finding no noticeable improvement using higher octane.

 

There are two types of programming used in engine parameters. Most engines are programmed to run on a specific octane level and will only retard ignition timing to compensate for bad gas if the knock sensors detect a problem. Those engines gain nothing by using higher octane fuel. Some engines have more dynamic programming which will advance ignition timing to just shy of the point where knock occurs to get the most performance out of higher octane fuel (within limits of course). Those engines include the Cyclone and Coyote series from Ford, the Hemi engines from Chrysler, and the newer LS series from GM along with a few others. They will run perfectly well on 87 octane but will show some increased performance on higher octane fuel. It's up to the owner whether the small increase is worth the cost.

Edited January 3, 2018 by TheWizard

[MaX83_ZA]

That report doesn't say anything that hasn't already been discussed... if the manufacturer says the vehicle requires high octane then always use it and if it says high octane recommended then the choice is yours - spend the extra money for a minimal increase in performance/mileage or save the money. If 87 octane is specified then most cars gain absolutely nothing by running higher octane. We ran our Ecoboost Edge on 87 octane all the time after trying both ways and finding no noticeable improvement using higher octane.

 

There are two types of programming used in engine parameters. Most engines are programmed to run on a specific octane level and will only retard ignition timing to compensate for bad gas if the knock sensors detect a problem. Those engines gain nothing by using higher octane fuel. Some engines have more dynamic programming which will advance ignition timing to just shy of the point where knock occurs to get the most performance out of higher octane fuel (within limits of course). Those engines include the Cyclone and Coyote series from Ford, the Hemi engines from Chrysler, and the newer LS series from GM along with a few others. They will run perfectly well on 87 octane but will show some increased performance on higher octane fuel. It's up to the owner whether the small increase is worth the cost.

 

I did say out of interest, didnt I? It gives some great dyno charts and make for an interesting read but now that I have read your detailed 2 paragraphs on premium vs regular, I guess I can remove the link because enough has been said. Sorry for offending you.

Edited January 3, 2018 by MaX83_ZA

[TheWizard]

Oh, not offended at all... this is an interesting discussion to which I like to contribute because I've spent the last 20 years working for a major oil company jobber so it's kind of in my wheelhouse. Please don't delete the link because it provides a lot of good detail which I just tried to summarize.

[WWWPerfA_ZN0W]

One other note I would add to the discussion: forced induction engines are very sensitive to detonation. One way to minimize the potential is to run higher octane fuel than needed. Especially if you do not use top tier fuel or fuel from a very busy gas station all the time. Having that cushion is basically insurance that you will not window your block, so you pay a little extra over time vs all at once.

 

With top tier fuels, usually the other main difference is the amount of detergents provided. 93 or premium fuel gets the most detergents, which can come in handy if you like to run 87 all the time, with a dash of 93 now and then. Shell VPower for instance, makes a noticeable difference on Ecoboost engines, compared to 93 from other brands. That said, there is some debate right now about detergents in GTDI engines with regards to certain undesirable combustion events. Fact is though, they do keep the fuel system and combustion chamber significantly cleaner than without. Once deposits form on DI fuel injectors, they are VERY hard to get off, so prevention is key.

[chefduane]

Yes, I run a top tier gasoline (Costco) almost exclusively. I keep a list of Top Tier providers laminated in my glove box for when we are on a trip. (My wife thinks I'm a bit nuts.) I occasionally run a tank of 93 through it and also a bottle Techron periodically. No other additives. I used to run a bottle of Marvel Mystery oil through my 4.0 SOHC Explorer every once in a while. Got 213k miles outta' her, but I figure the Edge can get by with a Top Tier gas and some Techron.

[akirby]

I'm not sure the "premium has more detergents" aspect is still true, at least with top tier vendors. I thought I had read the detergent levels were mostly the same now but I could be wrong.

[Tightanium]

Yes, I run a top tier gasoline (Costco) almost exclusively. I keep a list of Top Tier providers laminated in my glove box for when we are on a trip. (My wife thinks I'm a bit nuts.) I occasionally run a tank of 93 through it and also a bottle Techron periodically. No other additives. I used to run a bottle of Marvel Mystery oil through my 4.0 SOHC Explorer every once in a while. Got 213k miles outta' her, but I figure the Edge can get by with a Top Tier gas and some Techron.

Absolutely nothing wrong with doing what you do. But what bothers me is my brother in law has worked at a refinery now 31 years and has told me gas is gas. When a tanker pulls up to fill his truck with chevron gas they add the Techron at that point. And it's not even measured well because all they care is that load has Techron in it. Then a Shell truck pulls up and they use the same gas nozzle as chevron which comes from the same large storage tank. Add their additive and so on. He buys gas in some of the most crappy looking run down stations I've ever seen to save 5cents and has never had any gas related engine problems. I'm sticking to name brand gas. Makes me feel better.

[akirby]

Gas is gas but the additives are obviously different and I think that's what Top Tier is mostly concerned with - detergents, etc.

[TheWizard]

Absolutely nothing wrong with doing what you do. But what bothers me is my brother in law has worked at a refinery now 31 years and has told me gas is gas. When a tanker pulls up to fill his truck with chevron gas they add the Techron at that point. And it's not even measured well because all they care is that load has Techron in it. Then a Shell truck pulls up and they use the same gas nozzle as chevron which comes from the same large storage tank. Add their additive and so on. He buys gas in some of the most crappy looking run down stations I've ever seen to save 5cents and has never had any gas related engine problems. I'm sticking to name brand gas. Makes me feel better.

 

Your brother is absolutely right - basic gas is the same from all refineries. But basic gas (known as "unbranded" in the industry) has only the federally mandated minimum additives. The difference between brands is truly in the additive package and each keeps their formulations as a closely guarded secret. Top Tier fuels have additive packages that meet certain standards which are much higher than the government minimums. In the short term, unbranded gas will do no harm to your engine but over the long run Top Tier gas will do a better job of keeping your engine clean and running well.

[WWWPerfA_ZN0W]

The problems arise AFTER the gas leaves the refinery. Think of all the failure points in between en route to your vehicle's gas tank. In a perfect world, all tanks would be clean, there would be no water, no rust, no bacterial/algal growth, etc. That is why it is important to at least use a gas station that is BUSY, if a Top Tier station for some reason is not agreeable to you. That said, if that Top Tier station is not busy, it may not be as good over time as a no-name station that is busy. Every area will have different "best options".

[TheWizard]

In all but the most remote areas, you generally won't find stations that do so little business that they aren't refreshing their tanks regularly. It's much more of a problem with higher octane grades because those don't sell well even at busy stations but even our slowest dealer stores sell 21,000 gallons of regular 87 octane every month. With the common in-ground tank size of 10,000 gallons, and considering that they can't access the bottom 800 gallons or so, that means that they are turning their tanks about every ten days which is unlikely to be long enough to cause phase separation (the most common cause of "bad gas"). Our busiest stores get as many as three 9,000 gallon deliveries each day so there is a considerable range of volumes. But if you do get stuck buying from a low volume station, buy regular because they may not sell enough of the higher octane grades to keep it fresh... I've seen stores that don't sell 1,500 gallons of 93 octane in a month so the gas could get quite old.

 

Other things to watch for are the cleanliness of the pad (the concrete area around the pumps) and the speed of the pumps. A poorly maintained pad could indicate a general lack of care in maintaining their tanks, pump filters, and fill caps which could mean contamination of the fuel in the tanks. Unusually slow pumps generally indicate clogged filters which could mean that there's lots of water or debris in the tanks - stop pumping and go somewhere else.