|12-30-2016 04:45 PM|
It is not "snake oil" as you call it. You appear to be ignorant of the engineering that went into the Ti-VCT engine...
Ti-VCT stands for, "Twin, independent Variable Cam Timing". There are two overhead cams that operate the valvetrain in your car. There are, additionally, two knock sensors per cylinder that are designed to automagically (via oil pressure solenoid) adjust engine timing depending on the knock-index of fuel that you put into your car.
If you put in el-cheapo fuel, the engine will retard its own timing to prevent pre-ignition and knock (i.e. it will not destroy itself). So, to be clear, it WILL run just fine on 87 octane. BUT if you give it a higher octane, the engine will automatically advance timing to give you a slight performance gain. Whether that's worth the marginal increase in cost is completely open for debate, but the engineering that went into your engine is not debatable; it simply is what it is:
My own experiences are that premium fuel results in a modest, incremental performance gain. I have a 5-sp manual, and with premium I can generally keep my RPM's much lower without having to downshift. This means I can also pull hills in top gear that don't otherwise require me to downshift or lug the engine. This does result in some additional fuel economy (I have had a CDL for years, work in logistics, and happen to be a subject matter expert in this area).
As an aside, over the lifespan of your engine, lugging === bad. If you're able to prevent that with a higher grade of fuel (as I am able to do), you will probably get a few more miles out of it, so there may be indirect benefits there as well.
|12-15-2016 01:31 PM|
|cavedog309||88584 miles all Premium and most Non Ethanol .60$ more but this Little car will just shi* and Git throu the Twisties, Still Amazing while delivering 33 to 38 mpg. Here in the Northeast they put what they call oxygneators in the gas for the cold weather , You can see the fuel mileage dipp in the winter and oh about april march it will go back to 37 , 38 MPG.|
|12-15-2016 11:03 AM|
|Tigeo||Still seeing large (to me) delta in premium - regular cost here in VA. ~$0.60 or more here.|
|12-12-2016 08:27 PM|
Better for years to use the fuel that it's designed to work with, no options on that once you find the one that works best (usually the recommended one).
These are different, so it's a real personal choice and dependent on local prices. Prices to determine if MPG saves $, and preference for the performance or not. Running better isn't worth a nickel to some, $ per mile is all that matters.
|12-12-2016 07:11 PM|
Cars are inconsistent on the same octane,same driving so it is hard to say one way or another. A lot of the reason people run high octane is some what in their mind and simply can't put lower octane in their cars. I think I'm a little in that group with the Focus in part since the ECU will accomodate the higher octane but is the difference in perfromance a reality or just a placebo effect. I do get what seems like another 20 miles a tank with premium but cost-wise I think I'm spending a few more dollars a tank but doesn't bother me.
The 15.8 MotorTrend ran in the 2012 Focus SE (5 speed) was accomplished on 89 octane and is a very good time for a showroom stock MK3. Is running 91-93 really going to make a real world difference. A tune will be able to take advantage of extra octane but I'd be curious what a tuned bone stock Focus would run in the 1/4 vs untuned.
How much does a tune and higher octane effect a DCT equipped Focus with no other mods since they struggle to see the 15s in stock trim.
|12-12-2016 09:54 AM|
|Blackfocus86||Last time I tried this was with my 96 civic automatic. Conclusion was 87 octane was pretty consistent at 33.8 miles. With 91 it was 31.6 if I remember. Less mpg in the premium here in Cali using the same chevron station and pump for the most part|
|12-12-2016 09:51 AM|
|Blackfocus86||Currently testing 87 and will switch to 91 on my 2012 Focus manual. All I see are people arguing that they feel this and that but no real answer lol. I am manually calculating my mpgs while using the same gas station chevron here in California for more accurate report. I drive 70miles a day for work|
|12-11-2016 01:50 AM|
|felixthecat||Running a 91-93 octane tune helps.....|
|12-11-2016 12:23 AM|
|Chanandaler_Bong||I use premium going from my home (amarillo) to visit my mother in Tulsa. IF you use standard gas (usually 82) I have to stop and fill up in OKC or ill be rolling into Tulsa on fumes. If I go to the shell place and put in full on 97 octane, I can make it to Tulsa before the fuel light comes on.|
|12-05-2016 06:31 AM|
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