2.3 vs 2.7 compromise

[abe]

Genuinely curious for anyone who has a vehicle that has different power outputs based on octane ratings; can you actually tell the difference?

I felt a difference in my 2.7 f150, but I didn't really test it out scientifically. It could've just been me expecting more, so I felt it

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[mikegofficial]

This will be my first 4x4 but I've had a 96 Ranger, 02 GTI, 07 GTI and 17 GTI - all cars were a manual and I'm really looking forward to cruising around with the doors off.

I miss driving a manual so the 2.3L is where my head is at. I bet when I go off-roading that it'll be more of a learning curve but C'est la vie.

 

[TMP]

Genuinely curious for anyone who has a vehicle that has different power outputs based on octane ratings; can you actually tell the difference?

No you can not......octane is the measurement of the volatility of the fuel......the higher the octane the slower it burns.......putting high octane fuel in an engine designed for regular octane fuel is just a waste of money.

 

[Hoofnmouth]

When I get back to my place tomorrow or Sunday, I will show you what Turbo manifolds and cartridges with 225k look like. I think that you will be shocked. I replaced my manifolds when I developed a slight exhaust leak after 225k miles and since I was going all the way in there I decided to order a pair of new cartridges as preventative maintenance (because I thought they would be trashed too), but I was incredibly surprised and wrong. They looked amazing.

They are a component subjected to a horrible enviroment extremely hot on one side ,spinning like crazy on the other ,with little carbon seals in the middle keeping engine oil seperated 1920s technology made better by space age materials and manufacturing .
Ive seen plenty fail sooner than 3 yr. 36000 so one will be enough for me to get a manual trans ( another pos) if not for the manual option i wouldnt be waiting for my bronco,ford really let me down on this part.

 

[Rick Astley]

Absolutely could on an N/A 390 with a mild cam.

FE's were built at a time when 95-97 RON was standard.
Even running a FE without octane booster is lean.

Seems a strange comparison but yes, carbureted cars have massive power differences by RON.

 

[Rick Astley]

Genuinely curious for anyone who has a vehicle that has different power outputs based on octane ratings; can you actually tell the difference?

My daily driver is a 2018 Mazda6 GT (2.5 turbo, direct injection, similar manifold and cat layout to the Pinto 2.3 in Ranger/Bronco).

It has an advertised 227/250 hp and 310 torque, hp is rated at 87 and 91 octane, respectively.

There is a noticeable difference at specific RPM and under certain load (almost exclusively WOT), I've run about 3 tanks of premium in it for the 23,000 miles I've owned it.

The greater difference was my Mutsubishi Evo 9 when I had dual mapping and would bounce between 91 octane and E85 (which is effectively 108 octane), the extra 70 wtq at all wheels was noticeable and it was truly a different animal. But that involved blending fuels in the trunk and a chemistry set just to get 6 mpg of insane speed so you could do it again in about 2 hours since the tank was tiny.

Do I think most people will feel it in Bronco (regardless of engine)? Probably not, but if you need the 2.7 because it swells your undies, you'll most likely find the difference substantial.

But hey, at the right angle everything is a full 6" when you need those spare 2", am I right!?! (Or at least that's what goes on the dating profile)

 

[TJconvert2.7]

Has anyone noticed 2.3/2.7 indication on vehicle?

“bronco” on grille, bucking bronco on rear, trim level on fender... I haven’t noticed.

 

[ssolypop]

So I've been giving the 2.3L vs 2.7L engine a lot of thought and I think that I may have come up with a way in which the 2.7 may wind up actually being cheaper, and yes, this is me totally trying to justify the bigger engine to myself. Let's say, just for the sake of simplicity that I'm going to drive the Bronco for 100k miles. Also for the sake of simplicity, let's say that the truck is going to be SAS, so the comparable MPGs would be 18 (2.3) vs 17 (2.7).

Yes, I know I could run regular in either of them, but just for these purposes let's say that I want some degree of extra power beyond what the 2.3 gets on regular. If I went ahead and ran premium on the 2.3 in order to get the full specs vs regular on the 2.7 where I'd still get 315 hp/410 torque which is plenty. In my area right now, regular is $2.99 and premium is $3.94. So here's how that lands over 100k miles (obviously gas prices will vary here, but again just for simplicity's sake).

Cost to drive 2.3 SAS 100k miles with premium fuel at $3.94/gal and 18 MPG = $21,889.
Cost to drive 2.7 SAS 100k miles with regular fuel at $2.99/gal and 17 MPG = $17,588
Delta between the 2 = $4,301
Cost to add 2.7 to build = $1,895
Long term savings = $2,406

Thanks for patronizing me on my quest to justify my decisions to myself.

What you dont mention is the rest of your build. There are different ways to get the savings you're looking for... so let's have it, what model and options?

 

[Wanted33]

I just found a new excuse for picking the 2.7L. You sir could be my new hero.

 

[linbackr99]

Personally with the turbo - either one of them - I would only burn super anyway. I've noticed the difference with my Raptor 3.5 when I drop down to the Costco 'super' (which is mid-grade at best) in both mileage and performance. Each to their own but if the compromise if running regular unleaded in a higher performance engine it seems a poor decision. But if I was doing anything other than the WT I would absolutely be all in on the 2.3 - it's got plenty to offer!

 

[stm378]

What you dont mention is the rest of your build. There are different ways to get the savings you're looking for... so let's have it, what model and options?

I’m indecisive as hell, right now I’m split between OBX and BL which is a ridiculous conundrum on its own. Lux and tow with either one, MGV with BL, leather with OBX. The roast leather with the OBX is my favorite interior, but I’ve got some hopes still languishing that the WT leather interior just photographs poorly and actually looks good in person in which case just blow up my decision tree and start again.

 

[LHD]

generally speaking torque outputs will be within a few percent of each other regardless of the fuel used (in a vehicle that will adjust). The perceived acceleration will be the same in normal driving. In real life, the only time you will see a difference is in the top 1/3 of the tachometer. That means you only get the additional power if you are hammering it full throttle or close to it. Think about how many miles you go at full throttle vs. normal driving. It is a vanishingly small percentage of time. (You accelerate at full chat getting on the highway and then set the cruise control for 150 miles of steady state velocity. I am not going to bother paying an extra $0.70 a gallon for all 150 miles driven for the slight (maybe a tenth or two faster to 60 MPH) for the tiny amount of time it takes to merge on a highway (and if I am cutting it so close that 1/5th of a second is the difference between merging safely and having a wreck, I should have my license revoked). That would work out to be about $6 in extra cost for 1/5 of a second time savings.

Unless you live your life a quarter-mile at a time, no rational person would run premium unless it is for emotional reasons, which is super, you do you, nobody cares.

No you can not......octane is the measurement of the volatility of the fuel......the higher the octane the slower it burns.......putting high octane fuel in an engine designed for regular octane fuel is just a waste of money.

True, except these (boosted) motors are mapped to take advantage of the higher octane. Different boost curves, ignition mapping, EGT feedback, etc. based on the octane of the fuel. They will run on 87 and the 2.3 makes 270 hp/315 tq. but with premium its 300/325. Do you suppose you can feel an ~10% jump in hp or 10 lb./ ft. of tq?
Not likely, but it also depends where in the curve the gains are effected. It Would be nice to see that graph. Way up on the curve, I think it would be negligible. Boost increase down low, hmmmm…..

 

[mpeugeot]

They are a component subjected to a horrible enviroment extremely hot on one side ,spinning like crazy on the other ,with little carbon seals in the middle keeping engine oil seperated 1920s technology made better by space age materials and manufacturing .
Ive seen plenty fail sooner than 3 yr. 36000 so one will be enough for me to get a manual trans ( another pos) if not for the manual option i wouldnt be waiting for my bronco,ford really let me down on this part.

As someone who used to fabricate and dynotune forced induction systems, yes, I have seen lots of turbo fail prematurely. Usually there are several usual suspects that cause failures: excessive egts, excessive oiling, inadequate oiling, excessive turbine rpm, poor balancing, and poor quality control/assembly. So, yes, there is a lot that can go wrong, especially if you purchase some cheap chinese knock-off turbo.

However, think about the reliability of the average turbo-diesel engine, you don't see anyone not expecting hundreds of thousands of miles on a turbo-diesel. Well engineered turbo engines can be extremely reliable.

 

[mpeugeot]

I felt a difference in my 2.7 f150, but I didn't really test it out scientifically. It could've just been me expecting more, so I felt it

So, while not a factory tune, putting an aftermarket 93 octane tune on my 3.5 Ecoboost is night and day different. That said, you will lose a ton of power trying to run low octane fuel because the engine has to aggressively pull timing.

Don't expect one tank of 93 to make a difference, I suspect that the new ECUs will allow the motor will slowly adjust timings when it does not detect pre-igntion or knock for an entended period of time. This is how they achieve this, but put lower octane fuel in the motor and it will aggressively pull timings to protect the engine.

 

[AZ_Liberty]

I have owned cars that made higher HP and MPG on higher octane fuel. Never noticed the HP difference. MPG difference was very noticeable, but not enough to make up the difference in price.

Best mileage I ever got with that car was when I forgot to get gas before I left town and bought gas halfway between Phoenix and Tucson. That's outside the "smog area" and the gas was 100% gas and not 10% ethanol.

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