Do older 2nd gens have more power than newer 2nd gens?

I always ran (and still do) 91 just because it contains no ethanol in my region, but it will vary from region to region.

 

I've done some very unscientific measurements with 87 and 93 based on my 300 mile weekly commute. Using the same route, speed and brand of fuel...both 87 and 93 from the same Costco store. Every single time I fill a complete tank of 93 I always, without exception, have an additional 1/4 of fuel by the end of the week vs the 87.

I hesitate to even post that. Because I hear the naysayers gathering on the horizon now...with their charts, graphs, calculator and slide rules.

 

Could be interested, have the URD intake and sometime next week having the URD SPEC-U exhaust exhaust arriving. Replaces the Y-pipe with equal length tubes and a full cat-back.

 

No one is saying there is more power for any years of the 2nd gen. TTI is not what I am talking about. Tip In is different from the demanded load/accel pedal/throttle plate angle relationship which can use several maps cells to calculate the throttle angle that is actually commanded by taking into account IAM, intake air temp, intake pressure, MAF load, transmission gear and maybe some others. Tip in is how the EFI system compensates for the inrush of air and intake pressure rise on large throttle changes so that the AFR doesn't spike lean or rich. This shouldn't need adjustment unless injectors or post MAF intake system is changed.

A ECU datalogger should make it quite clear to see if there are any gains made by higher octane. Coarse/Fine knock feedback and IAM will show improvement if higher octane rated fuel allows for more timing advance, along with just seeing how far to the top/right of the ignition advance table the ECU is able to go before sensing knock and retarding timing.

I'd like to look into this myself if I can justify the cost of the HP tuners system.

 

I would love to know too. But it's not so important as to spend money on it in my case. As long as Costco continues to offer 93 octane under $2.50 I will continue to keep an eye on fuel economy. Maybe I can even figure out whether the possible gain is worth the price difference....which in Costco's case isn't that much

 

Yea, that's pretty unscientific. If you had hand calculated fuel mileage and given us some real numbers your post might have more credibility. Actually what you observed has been duplicated many times. It is pretty common for vehicles to get a little better fuel mileage when using higher octane fuel. But I've never seen anyone gain enough fuel mileage to offset the additional cost of the higher octane fuel. That is why some REAL numbers from your experiment would have helped.

With SOME vehicles you see enough difference in performance to justify the more expensive fuel. Especially if you tow. But with other vehicles there isn't any gain in performance.

 

I guess I’ll throw in something for thought.
Many later model Gen 2 have reported engine ping.
Could it be possible that the ‘15 had experienced engine ping, and the ECM has back off the timing.
It seems around the time the SAI System was added to the Gen2 trucks, we started see more reports.
There was even a TSB on the issue.
Some have even went with after market exhaust cam gears to help alleviate problem.

I truth, even this probably won’t make the difference you notice. (Or think you notice?)
Like previously mentioned, you really need to run them against each other.
Even then, you need to have the truck the same as in weight, tires, etc.

 

Like I said....

 

Just need some good data logging. The sensors will tell the story.

 

Yes, it could tell a lot things.
A good technician can get a pretty good idea of the over all “condition” of the engine.

 

I drove a 2018 while my 07's frame was being replaced and I had a similar experience.

 

This.