Originally posted by Aslyfox the HUD on the new to us 2016 GMC Acadia Denali we got 2 weeks ago ( at 35,200 miles ) makes it easy to track how fast you get away from a complete stop.
I am being very conscious not to " jack rabbit " away just because I am curious as too how good gas mileage I might be able to get
last weekend, on a trip from Topeka to Omaha, and driving in Omaha I got 18.8 mpg
it has a V6 and a towing package
the thing that is throwing me is that I mentally compare its range to the older, bigger and heavier 2002 Suburban
but then I realize the difference not mpg but tank size
the Suburban had a 32 gallon tank
the Acadia is 22 gallons
makes a difference indeed
Miles per gallon is an interesting subject. We have two cars, both large sedans. One is a 2007 Buick 6 passenger sedan and the other is a 2015 Impala, the newer style which is based on the GM...German Opel designed Epsilon II LWB (long wheelbase) platform.
The Buick has the older, but legendary Buick 90 degree 3800 cc V6, which has very good low and mid range torque. The car is around 3500 lbs and has a 4 speed automatic.
The Impala is also about 3500 lbs. but uses the GM 3.6 liter DOHC, 4 valves per cylinder, V6 engine...puts out 305 hp, has a 7000 rpm redline and a 6 speed automatic.
They both get about the same MPG. In the city the mileage is ok. On the highway the MPG of both cars is excellent, not too far from the highway MPG our previously owned Toyota Matrix with it's 1800 cc, DOHC 4 valves per cylinder, 4 cylinder and 4 speed automatic.
Some will say that's impossible, but the Toyota only got about 2-3 mpg better at highway speeds than our two large sedans with much bigger engines, Reason why was at highway speeds ( 60 mph) the higher gearing, the slippery aerodynamics of the large cars were better than our slab sided utility Matrix. At 60 mph the 126 hp Matrix engine was revving around 2600 rpm +/-...while the Impala with it's 305 hp engine and higher gearing , is loafing at around 1600 rpm or so. Couple that with what I would say...less aerodynamic drag with the Impala and the fact that on highways on the Canadian prairies around here...once you get to constant cruising rpm (using cruise control) the rpms are fairly constant, as there is little traffic.
Where our Matrix got significantly better MPG was in town, during heavy, stop and go traffic. Stop and go constantly worked to the smaller car's lighter weight (2500 lbs or so) and smaller engine...as the larger car had to move almost half a ton (1000 lbs) more from a dead stop over and over again in heavy city traffic.
Once out on the highway...both cars were going at a constant rpm (1600 rpm vs 2600 rpm) and the extra weight was not as much of an issue as in stop and go and the better aerodynamics of the Impala compared created less aerodynamic drag, compared to the more boxy utility styling of the Matrix.
Of course if the highway had heavy traffic and a lot of passing went on...constantly accelerating a heavier weight (large sedans) would take a toll on MPGs....more so on the heavier sedans, than the lighter Matrix.
My guess anyway.
I constantly (daily+) check MPG and cold tire , air pressure on our vehicles. Always keep my air pressure a bit more than factory recommendations to counter air pressure loss with cold. But I only keep the pressure a few pounds over ...too much is not good and can be detrimental to handling and tire life. Fortunately it's easy when you have an electronic tire pressure system check, that monitors individual tire pressure to the individual psi.