How to fix weird Knock Retard

[AJP turbo]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

[AJP turbo]

I wish some of u guys that had tunes would ask your tuner how much more spark advance of they run...not that u would get a straight answer anyway....but...I know that some are advancing the spark and relying on the knock sensor to ride the edge of knock for the purpose of running the most amount of spark the given fuel will handle..

I can set the tune in a manor that I run 87 octane And not only will u see 0 knock retard but the ecu will add more timing...it's all on how the base tables are set.

Adding 2-3 degrees is a quick way to get 20hp then u just let the knock sensor pull timing if it hears some knock....I think some of u guys are way to sensitive to a little knock retard now and again.

Not only are there tables in the tune to limit how much timing is added or pulled based on the knock sensor but also tables that control how quickly or slowly spark is added or pulled

Learned knock tables should be treated like stft...I'd like mine to hover around 0...if it's always on one side or the other then your tables need work...surprising the stock timing tables work amazingly well...looking at the tables ford spent a lot of time dialing in about the max amount of spark that can be tolerated at each load and rpm cell in the tune

[14 TUX BL]

The performance of our SHO benefits from Premium Fuel:

(below taken from 2014 Sales Brochure and Owner's Manual)

[AJP turbo]

Correct...our particular cars do benefit due to the tuning....some cars are only tuned for 1 fuel...our cars can make the best use of multi fuels....not all cars have learned knock logic built into the tunes but a lot of new cars do

[SHOdded]

AJ is correct.  Stock, my Edge only runs on 87 fuel.  I'd have to load a separate tune for 91 and a separate tune for 93 just to account for the octane difference!  The 2011+ Edge benefited from tuning for fuel octane adaptability, however.  Using higher octane fuel to make the engine "run better" when it is not tuned for it is primarily done to a) take advantage of the deposit-removing additives generally found in premium fuel, and/or b) cover up combustion issues that cause ping/knock.

[14 TUX BL]

Right aj, bone stock SHO's develop more hp when using Prem fuel:
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
EDMUNDS
http://www.edmunds.com/ford/taurus/2010/road-test-4/
"The result is 365 hp ... on 93 octane ... those of us in deprived 91-octane states should hit this number. The EcoBoost mill will run on 87 octane regular ... but the output will fall off a bit."
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Bottom line, we will lose some hp on a bone stock engine if we use Reg.

[SHOnUup]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

[FoMoCoSHO]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

Well, what are their testing methods? Just like the track, there are too many variables to know.

If there was any advantage to MPG with premium, you can bet Ford would lock it down to premium to get those extra CAFE points.....manufacturers are seriously under the gun with future fuel economy requirements....

[SHOnUup]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

Well, what are their testing methods? Just like the track, there are too many variables to know.

If there was any advantage to MPG with premium, you can bet Ford would lock it down to premium to get those extra CAFE points.....manufacturers are seriously under the gun with future fuel economy requirements....

From a TON of guys on ecoboosted page...doubt it was very scientific. But many mentioned the change in mileage on the same daily commute they always take. Could be them easing off the throttle a bit to reinforce the idea, but if was a wave of guys.

Rich

[wasinger3000]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

Well, what are their testing methods? Just like the track, there are too many variables to know.

If there was any advantage to MPG with premium, you can bet Ford would lock it down to premium to get those extra CAFE points.....manufacturers are seriously under the gun with future fuel economy requirements....

From a TON of guys on ecoboosted page...doubt it was very scientific. But many mentioned the change in mileage on the same daily commute they always take. Could be them easing off the throttle a bit to reinforce the idea, but if was a wave of guys.

Rich

I'll try 500 miles of 91 then 87 and see where it stands.

[SHOnUup]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

Well, what are their testing methods? Just like the track, there are too many variables to know.

If there was any advantage to MPG with premium, you can bet Ford would lock it down to premium to get those extra CAFE points.....manufacturers are seriously under the gun with future fuel economy requirements....

From a TON of guys on ecoboosted page...doubt it was very scientific. But many mentioned the change in mileage on the same daily commute they always take. Could be them easing off the throttle a bit to reinforce the idea, but if was a wave of guys.

Rich

I'll try 500 miles of 91 then 87 and see where it stands.

Awesome, I know you'll put more of a scientific twist on it.

Rich

[ShoBoat]

I can see getting a bit more economy with premium fuel like 91 over 87. I personally recorded a LOR of -0.03 when our explorer. The truck was pulling lots of timing to account for the crappy 87. Less power in theory would require more pedal to climb a given grade and maintain a given speed for example. Also towing a load. Will it run on 87 sure it will. To say the car/truck will not take advantage of the higher octane is nonsense. With how FMC controls their engines today it will. Is it the same as an after market tune um no lol. Keep in mind that our truck is a non EB 3.5.


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[wasinger3000]

So what's the consensus on knock in relation to fuel economy. Is it more economical to run a higher octane to prevent knock which will reduce the amount of fuel sprayed in compensation of the knock. Or is it not worth the price increase over 87? I'm taking the f150 on a trip over 4k miles and it's not tuned so no need for 91.

I've read that using 93 gets better mileage and ends up being same money spent as using 87...but your vehicle would appreciate the higher octane, and is better for it.

Rich

Then u read a bad article...a fuels octane rating is its ability to resist preignition..common myth that higher octane yields better mpg and burns hotter....running higher octane fuel than what the vehicle was tuned for will only increase operating cost...the car doesn't appreciate anything....commanded lambda will remain the same no matter the fuel being used...

I've only watched about a 100 guys report on better mileage in their F150 ecoboost by moving up to premium...they all must be lying?

Rich

Well, what are their testing methods? Just like the track, there are too many variables to know.

If there was any advantage to MPG with premium, you can bet Ford would lock it down to premium to get those extra CAFE points.....manufacturers are seriously under the gun with future fuel economy requirements....

From a TON of guys on ecoboosted page...doubt it was very scientific. But many mentioned the change in mileage on the same daily commute they always take. Could be them easing off the throttle a bit to reinforce the idea, but if was a wave of guys.

Rich

I'll try 500 miles of 91 then 87 and see where it stands.

Awesome, I know you'll put more of a scientific twist on it.

Rich

I'll do my best. Problem is this is all a one way kinda trip so not one mile will be the same as the last. That and the truck is still "breaking in". It's finally getting 18 mpg instead of the 14 when it was brand new.

[ZSHO]

I must agree that there is to many variables to take into consideration,because every SHO,truck have slightly different aspects in performance,economy, and at the end of the day it all comes down to the month and year your vehicle was manfactured. Z

[SHOdded]

I can definitively say that with my Edge, at one particular Exxon station, using the same routes, I saw differences in mpg of up to 1.5, between 87 and 93.  That was with worn spark plugs, mind you.  With new plugs in place, it doesn't hardly vary.