Is the official 405 posted horsepower on 87 octane?

[Critical Habitat]

Ford also warns that RR owners using regular unleaded in higher altitudes risk potential engine damage. From the online interactive owner's manual.

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[Ivan Baez]

the raptor is prone to pinging if low quality fuel is used.

 

[jrRaptor]

looks like figures are from 91 octane

hmm, I read the 3.0 was DI only like the 2.3, but this chart says different.

That chart is wrong. DI only. There's another thread floating around with this topic from last year and it was a doozy lol. You can literally go out and look at the engines now since a lot of 24MY Ranger's have been delivered and see that it is DI.

 

[millertime496]

Well the elevation thing kind of sucks, the gas up in em colorado is trash. Wish I had the change for a bigger tank right now. Still havent heard back if its self calibrates its distance to e. I wouldnt think so, so could I live with not knowing that, would the guage still function????

 

[nikhsub1]

When you run LESS than 91 octane the truck is constantly relying on the knock sensor to retard timing and pull boost. In lamens terms, that means that your engine is detonating and once that is detected the computer pulls back timing and boost. Detonation is one of the absolute WORST things you can do to a motor.

Y'all are familiar with 'flat' in EQ settings? Well, think of 91 octane as flat for the computer. See, 93 isn't available everywhere, so most MFGRs calibrate things to 91 octane. 93 certainly won't hurt, but it really won't get you any more than 91.

Bottom line is, if you use anything less than 91 you are constantly relying on the knock sensor to dial back timing and boost when it detects detonation.

 

[Roverhound]

What's the compression ratio on 3.0L RR engine?

According to the chart posted above, 10.5:1.

 

[Lion77]

You also give up considerable performance on 91 to 93 for the ability yo scale back fuel octanes. That is the basis of where all Ford Performance Pro Cals derive their gains.

They eliminate the need to scale back knock if someone suddenly switches from 91 back down to 87. The OE calibration can only get so aggressive on 91 such that if you then refill with 87, the knock isnt so sever it causes immediate damage, allowing the ecu to quickly scale back timing advance and adjust fueling.

The Pro Cal is what Ford could have given you if they eliminated the need to safely run on anything below 91. Thats why even for the 2.3L or 2.7L which are not performance engines, they can gain power and torque from a Pro Cal by eliminating low octane.

I understand why they do that, your average Joe doesnt understand fuel grades, imagine how many people would accidentally fill up with 87 or 89 and trash an engine if the factory cals couldnt scale back...my wife didnt understand that until I explained it to her, so thats really the engineering reason not to just do a Pro Cal on everything turbo from their factory, its a safeguard, plus a lot of times people are using their cars to go get groceries, where they dont need the performance, so they can run 87 for mundane uses at light loads to save on gas.

But in any high stress uses, like towing, driving at high altitude or performance driving it makes a big difference even on the stock cal. So for something like the RR, I see no reason to ever run 87 aside from an emergency where I couldnt find anything but 87, so I carry my procal in the glove box just in case i need to flash back in that one rare instance to run 87 til I can find a station with 91 or higher (plus it can read and clear DTCs if I run into an issue on the road).

There's a thread on this forum where someone towed a camper 1,200 miles and started out on 87 on a stock 2.3L XLT. He got about 8mpg...then he switched to 89 on the next tank and got a few mpg better (10 to 11 I think) Finally he bit the bullet and filled up on 91 and got 12 -13 and said he will never again run anything below 91 for towing (both fuel cost and performance or lack there of).

I did the math on the fuel cost and had he just run premium from the start he would have saved over $100 in gas becuase the massive hit to efficiency more than offset any savings in cost per gallon, aka his mileage tanked so badly during towing on 87 he was actually spending MORE money.

Turbo engines of any size or configuration benefit significantly from premium, not just power but also fuel economy.

Also larger displacement engines tend to be less octane sensitive. So the 2 3L, 2.7L and 3.0L are all going to see bigger performance hits from low octane than the 3.5L. But at the end of the day, turbo engines thrive on knock resistant fuels (aka more thermally stable) since theres a lot more heat to deal with. Just run premium and keep up with maintenance, use full synthetic oils and avoid frequent short trips if possible (less than 5-10 miles) or youll need induction cleaning services.

 

[Lion77]

And while there is no published papers on how big of a hit HP takes on a stock 3.0L going from 91 down to 87, its probably 30 to 40 hp. Our 2018 CX-9 would lose 27 HP from 91 to 87 as puished by Mazda and that was just a 2.5L single turbo engine.

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