Was it the Techron or just coincidence?

[ATL Sparty]

Just returned from one of my twice-a-year round trips between Georgia and Michigan (880 mi one way). I typically have gotten 30-31 mpg on those trips. On the trip up last week I barely made 29 mpg. Now, my dream boat passed the 100k mark on that particular trip and I have not done anything since I have owned the car to address the carbon buildup that undoubtedly exists in the GDI engine. For the trip home I added a bottle of Techron to the tank for my initial fillup. I was very happy to watch the mpg indicator vary from 30-32 mpg during the trip home and then settle at 31.5 when I pulled into my driveway. A few other things: 1. I traveled the exact same route on both trips (except for the exits taken, but I never go further than half a mile from the interchange.) 2. I encountered no accidents or slowdowns either way (I even sailed through Cincinnati w/o incident). 3. As always, cruise was set for 75 mph (even in Michigan where 75 mph is the legal limit for most rural freeways.)

So, what do the experts here say? Could whatever cleaning the Techron might have done improved the mileage that much

 

[2for1]

Doubtfull that it cleaned up any carbon buildup. But it could have cleaned up your injectors.

 

[JEBIV]

cooler outdoor temps ?

 

[Dad2Two]

wind direction?

 

[Amgil]

Techron and other cleaners like CRC has a chemical called PEA which WILL absolutely clean injectors, but thats it. It’s possible but unlikely that it increased mpg.

As for your valves and runners, The only thing that will get the carbon off them is a manual cleaning or media blast. Doing this would absolutely give you a small bump in fuel economy but not much.