Focus Fanatics Forum banner

Status
Not open for further replies.
1 - 20 of 103 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
Hey guys I'm new to the focus world. I just got a 2014 focus se 6 sp auto winter package I'm only at 2100 miles. I got gas today and the only non ethanol fuel available was 91 unleaded I decided to fill it with that. Will 91 harm my engine in anyway? Will the engine burn it correctly. Any advice would be helpful! Thanks
 

·
Registered
Joined
·
307 Posts
The only harm 91 (93 ?) will do is to your pocketbook <flame suit on>
 

·
Focus Addict
Joined
·
14,132 Posts


An excerpt from the 2012 Ford Focus owners guide.

Premium fuel will provide improved performance
The only reason this car can even run 87 octane is due to the gasoline direct injection combined with variable camshaft timing that can pull timing to avoid spark knock on a 12:1 compression engine running on the volatile 87 octane that is more easily pre-ignited.
 

·
__________/\__
Joined
·
2,183 Posts
Hey guys I'm new to the focus world. I just got a 2014 focus se 6 sp auto winter package I'm only at 2100 miles. I got gas today and the only non ethanol fuel available was 91 unleaded I decided to fill it with that. Will 91 harm my engine in anyway? Will the engine burn it correctly. Any advice would be helpful! Thanks
You are lucky that you can buy gas that is ethanol free. It is totally unavailable in the DFW area unless you source it from a specialty supplier or perhaps a marina.

If you can afford it, run 93 octane and preferably run a top tier fuel.

Here's why:
http://www.toptiergas.com/

Retailers that sell top tier gas
76 Stations
Aloha
Arco
BP
Chevron
Conoco
Costco Wholesale
CountryMark
Entec Stations
Express Convenience Centers
Exxon
Hawaii Fueling Network (HFN)
Holiday Stationstores
Kwik Trip / Kwik Star
MFA Oil Co.
Mobil
Ohana Fuels
Phillips 66
Quik Trip
Road Ranger
Scheirl Oil
Shell
SuperAmerica
Texaco
Tri-Par Oil Co.
 

·
Registered
Joined
·
52 Posts
Hey guys I'm new to the focus world. I just got a 2014 focus se 6 sp auto winter package I'm only at 2100 miles. I got gas today and the only non ethanol fuel available was 91 unleaded I decided to fill it with that. Will 91 harm my engine in anyway? Will the engine burn it correctly. Any advice would be helpful! Thanks
If anything, it will run better. I only put premium (usually 93 around here) in mine. There was a long thread a while back discussing octane.
 

·
Rubber Side Down
Joined
·
2,415 Posts
I'm lucky enough to live on an island with the only station within miles that has ethanol free fuel. The only grade they have that's ethanol free is 91. That's all I use.
 

·
Registered
Joined
·
2,517 Posts
I only put premium, usually 93 around here in mine. The Focus runs better, smooth, more responsive. BTW the other gas available is 87, I tried once, never went back. I stay with the 93
 

·
Registered
Joined
·
290 Posts
The odd thing is that my 2013 manual does not have that statement. I doubt it is any less true, but for some reason they decided to remove the statement. Maybe for legal issues, who knows.

Delaying the spark is how engines take advantage of higher octane fuel. Higher octane fuel does not ignite as quickly/easily, so they can wait longer to ignite it (high octane fuel does not have more energy in it - unless of course it also has no ethanol in it, but that has nothing to do with the fact that its higher octane). 87 octane fuel would ignite on its own (like a diesel engine I suppose - due to the compression/pressure) if the timing was delayed too long.

My local "no name" station (Fasttrac/Fastrac) has 91 octane with no methanol, which should have around 3% more energy ion it since methanol has 30% less energy in it (10% x 30% = 3%). But it costs at least 10% more than 87 octane.


An excerpt from the 2012 Ford Focus owners guide.
[/QUOTE]
 

·
Registered
Joined
·
220 Posts
BS on cars designed for 87 octane running better on 91. BS.
 

·
Registered
Joined
·
4,328 Posts
BS on cars designed for 87 octane running better on 91. BS.
If this were an older car, I'd totally agree - but I don't.

When I use 87 in the summer, my throttle response is pitiful. I basically have to floor it during left turns and on-ramps, etc. When I use 91, I don't have to do that. In the winter, it doesn't seem to make nearly as much of a difference - but that could be due to the outside temperature or all of the extra ethanol they're putting into the gas for the winter.

Don't knock (pun intended) it 'til you try it!

To sum up, if the car’s handbook says that premium petrol is “recommended” (rather than insisting it is “required”), then the engine will automatically adjust itself to run smoothly on a lower octane fuel. Because of the retarded ignition, the engine will, of course, produce less power, and have slightly higher fuel consumption. But the poorer fuel economy is likely to be outweighed by the savings at the pump.
http://www.economist.com/blogs/babbage/2012/09/octane-ratings

Using a higher octane fuel than recommended will not always make a difference, especially in older vehicles. In newer vehicles however, especially turbocharged or high compression performance vehicles, the higher the octane rating, the better. In these modern engines, equipped with variable timing and knock sensors, the use of a higher octane fuel may allow advanced ignition timing and more performance-oriented engine settings. This in turn, can improve throttle response and available power.
http://www.autos.com/car-maintenance/choosing-the-right-octane-level-for-your-car
 
  • Like
Reactions: Arco-Zakus

·
Registered
Joined
·
220 Posts
It's not even worth arguing about. If folks wanna put premium gasoline in their economy cars then so be it.
Agreed. If you want to perpetuate the myth and lighten your wallet faster, so be it.
 

·
__________/\__
Joined
·
2,183 Posts
BS on cars designed for 87 octane running better on 91. BS.
I grew up racing small block Chevys. In those days, tetraethyl lead was added to gasoline help reduce engine knocking and boost octane ratings. We ran high compression in those V8 engines. When emissions laws clamped down on our fun and in the absence of lead, auto manufacturers had to drop the compression in engines to try to keep knock at bay. (and NOX under control)

The higher the octane rating, the more compression the fuel can handle. Your MK3 Focus has a rather high 12:1 compression ratio and the only reason it can tolerate 87 octane fuel is that the direct injected Ti-VCT can pull timing. When you run 91 or 93 octane fuel, your engine will not need to pull timing and you should see improved power and enhanced drivability.
 

·
Registered
Joined
·
290 Posts
Cars aren't "hard coded" to only run on one octane anymore, just like Corvettes can run on 87 octane, but with less power. Sounds like the Focus doesn't take much advantage of the higher octane though seeing how Ford downplays it in the manual, and took the statement out after 2012.

Anyhow, Ford says the car takes advantage of higher octane fuel in black and white in the 2012 manual, so hardly is it 100% false. It's still a waste of money though, won't recoup the extra fuel cost.

Also, if a car or bike doesn't adjust the timing, using higher octane fuel might be bad in that it won't ignite as soon/quickly as the car is expecting. Could end up with some unburned fuel, or at least "non-optimal" ignition.
 

·
Registered
Joined
·
307 Posts
Would octane booster added to 91 be even better than just 91 ? STP makes some, just think you could restore lost power and performance clean the injectors and save gas by keeping the fuel system clean all at same time [ninja]
 

·
Registered
Joined
·
290 Posts
This guy is right:

......
The higher the octane rating, the more compression the fuel can handle. Your MK3 Focus has a rather high 12:1 compression ratio and the only reason it can tolerate 87 octane fuel is that the direct injected Ti-VCT can pull timing. When you run 91 or 93 octane fuel, your engine will not need to pull timing and you should see improved power and enhanced drivability.
.....

Nobody is more "anti high-octane" than me - for the majority of vehicles that are not designed to handle it. (especially funny when others who own the same carbureted bike as me use high octane).
I use 87 in my Focus except for 1x for the heck of it I used 91 octane that had no ethanol in it.

PS: Cold air is denser is why you have more power in the cold.
 

·
Focus Addict
Joined
·
14,132 Posts
BS on cars designed for 87 octane running better on 91. BS.
Let us see what's what:[idea]

Static Compression ratio: 12:1 (Duratec 2.0 L in the previous Focus had a 10.5:1 compression ratio) a high compression ratio traditionally favors high octane fuel as lower octane fuel will more readily detonate and cause issues.

Variable cam shaft timing: Twin-independent with camshaft phasing - allows for various states of valve overlap combined with the timing and spark advance and retard which allows the engine to adjust it's operating perimeters on the fly taking advantage of various octane levels.

The car was not developed to run only 87 octane, but they can't sell an economy car that can't run on 87 octane as no one wants to be forced to put high octane fuel in an economy car just to get to and from work.
 

·
Premium Member
Joined
·
44,595 Posts
Check this post that includes results from a similar car:http://www.focusfanatics.com/forum/showpost.php?p=6708985&postcount=32

Agree with block, suss etc., with more active adjustments avail. the engine can take advantage of "better" fuel.

It's NOT the relative "stone age" of the 80's, when C/R's were so low that high octane in an engine not designed for it was a problem. Engine basic designs hadn't changed, and ones designed originally for better fuel & higher C/R's were detuned with lower C/R as part of meeting emissions regs. & ability to use lower grade fuel.

block will appreciate the story of a new BMW R80 whose owner decided to treat it to a tank of high octane for it''s second tank full. Cycle wouldn't even start once that fuel got into the carbs. Had to cart it back to the shop, drain & replace the fuel, and deliver it back running fine again.
 
1 - 20 of 103 Posts
Status
Not open for further replies.
Top