My wife, I and the dawg left Christmas morning to drive to Manzanillo Mx. Close to 4,500Kms over 5 days in our family-truckster 2019 Dodge minivan. I reset the MPG (in our case Litres per 100 kms, I'll let you do the conversions) before we left.
This first photo is the dash display taken at Laredo Tx after about 3,000Kms on 10% Ethanol fuel. This is typical of what we see for hyway mileage in Canada (closer to 9l/100Kms because we are mostly driving 80Km/hr hyways). We filled up in Laredo before crossing into Mx to take advantage of the cheap gas. Note that from our home in S. Ontario Canada to Laredo is mostly flat with a few rolling hills. The temperature ranged from just below freezing when we left to mid 20's C when we got to the border. It was also raining a good part of the way.. I thought cool air and mist were supposed to improve MPG?

Next photo below we are south-west of Matehaula Mx and running on all Mx fuel now. I reset the fuel economy display as we had been running some USA fuel mixed with Mx fuel. Also we climbed some long mountain passes requiring manual shift-downs. We filled up from near empty, so now we are running almost pure Mx fuel. The terrain here is mostly level flat plateau at about 2,000m (~6,500Ft) ASL.
I was thinking Mx gas was ethanol free, but Google says otherwise.

Next photo below we are in some large rolling hills, not mountain passes but making the soccer-mom van do some work. I did not reset the fuel economy display from above.

Next photo I took because the van was just about to turn over to 100,000 Kms. You can see we are climbing a good size hill.

Final photo we are at our destination on the Pacific coast. So we still got 7.9l/100Kms over the last `1,000Kms in hotter temperatures and some mountain passes.
This is our 4th time driving down and I have observed much better fuel economy in Mexico every time. I know its not a GMC, but I suspect one might see improved MPG with it was well. Any ideas why?

This first photo is the dash display taken at Laredo Tx after about 3,000Kms on 10% Ethanol fuel. This is typical of what we see for hyway mileage in Canada (closer to 9l/100Kms because we are mostly driving 80Km/hr hyways). We filled up in Laredo before crossing into Mx to take advantage of the cheap gas. Note that from our home in S. Ontario Canada to Laredo is mostly flat with a few rolling hills. The temperature ranged from just below freezing when we left to mid 20's C when we got to the border. It was also raining a good part of the way.. I thought cool air and mist were supposed to improve MPG?

Next photo below we are south-west of Matehaula Mx and running on all Mx fuel now. I reset the fuel economy display as we had been running some USA fuel mixed with Mx fuel. Also we climbed some long mountain passes requiring manual shift-downs. We filled up from near empty, so now we are running almost pure Mx fuel. The terrain here is mostly level flat plateau at about 2,000m (~6,500Ft) ASL.
I was thinking Mx gas was ethanol free, but Google says otherwise.

Next photo below we are in some large rolling hills, not mountain passes but making the soccer-mom van do some work. I did not reset the fuel economy display from above.

Next photo I took because the van was just about to turn over to 100,000 Kms. You can see we are climbing a good size hill.

Final photo we are at our destination on the Pacific coast. So we still got 7.9l/100Kms over the last `1,000Kms in hotter temperatures and some mountain passes.
This is our 4th time driving down and I have observed much better fuel economy in Mexico every time. I know its not a GMC, but I suspect one might see improved MPG with it was well. Any ideas why?

