I think it's generally understood that our trucks are tuned/built to run on regular unleaded if the engine is stock. Especially for normal everyday driving regular unleaded is a must.

What (if any) driving scenarios would necessitate the need to move up to plus or premium unleaded? Road trips? Higher elevations? None?

 

I was told if it begins to knock upgrade to midgrade. some people say you get better MPGs but I really don't want to start that again.

 

I'm with you. I don't want to touch this one. But if you ask my opinion my training has told me that you only need higher octane with higher compression or altered timing. The ping scenario comes from the idea that carbon build up increases compression causing pinging. So higher octane should stop the symptom but not fix the cause. That's all I have to say. Everyone else can argue mileage and power and racing fuel.

 

I use jet b in my truck runs great for 3 seconds until the block melts

 

I've had to chase down a ping issue once in my truck and I used both plus and premium and it stopped the pinging, but I knew something wasn't exactly right, so I seafoamed it through the booster hose and that stopped the pinging and I was able to go back to regular.

I see that some don't want to touch the question.

I'm not looking to start WW III with the original question as we all know some topics can set off fireworks. I'm just looking for general feedback. Post what you think.

 

Actually, you guy's are doing just fine!

Octane delay's the fuels ignition. In our stock setups, W/ our stock compression engines, the fat lady's done singing regarding the cylinder firing, but when higher octanes are used, some fuel is left undetonated. This causes deposits.

Deposits start wicking fuel which then detonates out of sequence once combustion chamber temperature Ping threshold is reached. Very easy to reach that temp...very hard for the temp to return below that temp once reaches?

What to do...What to do?

The problem for the most part is the temp your cylinders reach. Octane is our stoke low compression engine's version of heroin. The fast fix. the most fuel let undetonated lowers the combustion chamber temps, by providing something called "quench effect".

However this causes more deposits, which causes higher temps, which requires even more "quench effect' not to ping. Until you run out of available higher octanes. Which leave you w/ unquenchable ping.

Keep in mind, while your chasing up the octane ladder, 87 octane has better overall combustive properties. The higher your engines octane habit becomes, the less it is likely to digest 87 octane w/o ping.

When is it ok the bump up an octane w/ our stock compression engine? I'll be back, I need a break!

 

Read this:
https://www.f150forum.com/f10/about-...ng-bump-53159/
(Especially the "getting your duck's in a row" part)

I used my truck as the test dummy for the ignition system upgrade & timing bump after a crap load of research on how to do it safely & get the most out of it.

I've done every thing denoted & run 16 BTDC w/ 87 octane w/o a hint of ping. However, I do run 89 octane on long haul road trips for insurance. I've run 18 BTDC, but don't see much if any gain compared to 16 BTDC, So I don't see any point to it. When bumping timing alway err on the side of safety.

Anybody bumping their timing, or has a problem w/ digesting 87 octane, Deposit removal for sure, & I reccomend you add a bottle of "Water Wetter" to help you stay under the ping threshold. It's all about combustion chamber heat & the transferring away of that heat as it occurs. Once Ping threshold is reached, it's hell getting the temp below that afterwards w/o shutting off the engine.

Also, higher temps are your engines greatest enemy, quickly shaving thousands of miles away from it's life expectancy:


So, with occasional Seafoaming of combustion chambers (I don't efen add to my oil anymore since I desludged it & switched to full synthetic) efficient cooling, a clean sludgeless engine, synthetic fluids w/ superior lubricity, better thermal transfer properties, & superior resistance to degradation due to continual thermal fluctuations...Your engine will lead a long & trouble free life!

 

I just remembered something that happened to me a while back. I'd ran out of gas right in my driveway. I was doing 1 gal. MPG tests & switching from tank to tank. Forgot & skipped a fill up.

I hoofed it over to the gas station & got a gallon of gas. I thought, "What the heck!" I got a gallon of 91 octane. I put it in my truck & it wouldn't even try to start.

Keep in mind I'm running a 60K volt coil.



Stock plug gap is .044. I'm running modified stock copper cores, side gapped out to .056 (later changed to .054)

My base time was set to 16 BTDC.

The 91 octane was unable to produce sufficient cumbustion to start the engine. It's controlled properties did not allow the wider gap to fire it. Even w/ a more provocative spark kernel size. I had to have the superior overall combustive properties of 87 octane.

Went back for a gallon of 87. Put it in the rear tank & the girl fired right up.

This points out the difference in the combustive properties between octanes.