White Dog
Senior Member
Since I was driving from Winnipeg to Calgary and back along the exact same route to pick up the new Grandby, I decided it was great opportunity to carry out a mileage experiment. The distance is 1350 km (840 miles) each way. The eastern half is quite flat and the western half is tall rolling prairie. The weather was about the same both ways, cool (4C to 14C – 14F to 58F) and a mixture of broken clouds for about half and flog/light rain for the other half. With one exception (see below), the winds were light (5 kph to 10 kph – 3 mph to 6 mph) and crossing the highway.
My truck is a 2011 Toyota Tundra with a 5.7 l V8 and a 6-speed automatic transmission. It is the double-cab long box 4X4 model. I weighed the truck at a provincial highway weigh station empty on the way out and again with the camper at the same station on the way back. Empty, the scale said the truck weighed 2612 kg (5746 lbs). With the camper, it said the weight was 3287 kg (7231 lbs) which included a full water tank. So the camper added 625 kg (1375 lbs). This is within 50 kg (110 lbs) of what I calculated it should weigh when I ordered the camper back in November based on the weight figures from FWC.
To minimize my effect on the mileage, I used cruise control whenever it was safe to do so. In Manitoba, the speed limit is 100 kph (62.1 mph) and in Saskatchewan and Alberta its 110 kph (68.4 mph). On the way out empty, I travelled as close to the speed limit as possible. On the way back with the camper, I held a constant 100 kph. The Tundra had no difficulty dealing with the weight and speed. I didn’t use the Tow/Haul feature. It simply wasn’t necessary. Certainly the transmission shifted down sooner and up later on hills with the camper and shifted down on some hills that it wouldn’t have when empty. That is to be expected.
So, what did I find out? Traveling empty, the average mileage at 100 kph was 24.12 mpg (imp) (20.09 mpg (US)). (Note: Being Canadian, I will give the mileage in imperial gallons first followed by the mileage in US gallons in brackets). Surprisingly, this was a touch higher than the Toyota rated mileage of 24 mpg but I typically get 23 to 24 mpg with this truck if I drive carefully, the weights are low, and I’m not fighting a wind. When I increased speed up to 110 kph, the mileage dropped to 20. 5 mpg (17.0). I was a bit surprised at this difference. I guess it is a good example of ‘slow down to save gas’. Coming home with the camper holding a constant 100 kph, the average mileage was 19.7 mpg (16.4) or 18.3% less than empty at the same speed – surprising, not that much less than cruising empty at 110 kph though. At the end of the first day on the return trip with the camper, a 20 to 25 kph (12 to 16 mph) headwind (based on local radio reports)came up for about 4 hours. The mileage during this time dropped to 18.3 mpg (15.2) or 24% from the recorded mileage empty at the same speed. Obviously, the headwind had an effect which is to be expected given the increased frontal area when carrying the camper.
What do I conclude? I can expect the camper to reduce my mileage by 15% to 25%, the higher figure being with headwinds. Considering the weight and increase in frontal area, I feel this quite reasonable. When towing my 24’ travel trailer, the mileage is reduced by 40% to 50%. I am also convinced that using cruise control while hauling the camper reduces mileage. In the rolling country of Saskatchewan, I could feel the truck constantly trying to accelerate and decelerate in order to maintain the set speed. By careful manual driving (no cruise), I believe I will be able to increase mileage by at least another mpg. I do this with the trailer all the time. I was also very pleased with the way the Tundra carried the camper. I knew the camper was there and the predictable braking and acceleration effects were noticeable but the truck felt like it had lots of reserve left.
Other observations: I recorded the estimated average mileage from the Tundra’s onboard computer with each tank of gas. It was always within 3% of the true mileage - quite good actually. This is not just an interesting anecdote. It means that the estimate of range from the same computer is pretty reliable. This is a useful bit of information. Toyota seems to have included about a 10% reserve in the calculation, meaning that when the estimate says ‘0’, there is still 10 l of gas in the 100 l tank.
Obviously, this is only one trip. I will certainly see if I can increase mileage by driving without cruise especially with headwinds. I tried to control as many of the variables as possible during this trip but still there has to be some ‘human’ and ‘environmental’ effects that impact mileage. I would be interested in hearing what others have to say. Everyone drives differently and with the price of gas, anything that increases mileage is ‘a good thing’.
My truck is a 2011 Toyota Tundra with a 5.7 l V8 and a 6-speed automatic transmission. It is the double-cab long box 4X4 model. I weighed the truck at a provincial highway weigh station empty on the way out and again with the camper at the same station on the way back. Empty, the scale said the truck weighed 2612 kg (5746 lbs). With the camper, it said the weight was 3287 kg (7231 lbs) which included a full water tank. So the camper added 625 kg (1375 lbs). This is within 50 kg (110 lbs) of what I calculated it should weigh when I ordered the camper back in November based on the weight figures from FWC.
To minimize my effect on the mileage, I used cruise control whenever it was safe to do so. In Manitoba, the speed limit is 100 kph (62.1 mph) and in Saskatchewan and Alberta its 110 kph (68.4 mph). On the way out empty, I travelled as close to the speed limit as possible. On the way back with the camper, I held a constant 100 kph. The Tundra had no difficulty dealing with the weight and speed. I didn’t use the Tow/Haul feature. It simply wasn’t necessary. Certainly the transmission shifted down sooner and up later on hills with the camper and shifted down on some hills that it wouldn’t have when empty. That is to be expected.
So, what did I find out? Traveling empty, the average mileage at 100 kph was 24.12 mpg (imp) (20.09 mpg (US)). (Note: Being Canadian, I will give the mileage in imperial gallons first followed by the mileage in US gallons in brackets). Surprisingly, this was a touch higher than the Toyota rated mileage of 24 mpg but I typically get 23 to 24 mpg with this truck if I drive carefully, the weights are low, and I’m not fighting a wind. When I increased speed up to 110 kph, the mileage dropped to 20. 5 mpg (17.0). I was a bit surprised at this difference. I guess it is a good example of ‘slow down to save gas’. Coming home with the camper holding a constant 100 kph, the average mileage was 19.7 mpg (16.4) or 18.3% less than empty at the same speed – surprising, not that much less than cruising empty at 110 kph though. At the end of the first day on the return trip with the camper, a 20 to 25 kph (12 to 16 mph) headwind (based on local radio reports)came up for about 4 hours. The mileage during this time dropped to 18.3 mpg (15.2) or 24% from the recorded mileage empty at the same speed. Obviously, the headwind had an effect which is to be expected given the increased frontal area when carrying the camper.
What do I conclude? I can expect the camper to reduce my mileage by 15% to 25%, the higher figure being with headwinds. Considering the weight and increase in frontal area, I feel this quite reasonable. When towing my 24’ travel trailer, the mileage is reduced by 40% to 50%. I am also convinced that using cruise control while hauling the camper reduces mileage. In the rolling country of Saskatchewan, I could feel the truck constantly trying to accelerate and decelerate in order to maintain the set speed. By careful manual driving (no cruise), I believe I will be able to increase mileage by at least another mpg. I do this with the trailer all the time. I was also very pleased with the way the Tundra carried the camper. I knew the camper was there and the predictable braking and acceleration effects were noticeable but the truck felt like it had lots of reserve left.
Other observations: I recorded the estimated average mileage from the Tundra’s onboard computer with each tank of gas. It was always within 3% of the true mileage - quite good actually. This is not just an interesting anecdote. It means that the estimate of range from the same computer is pretty reliable. This is a useful bit of information. Toyota seems to have included about a 10% reserve in the calculation, meaning that when the estimate says ‘0’, there is still 10 l of gas in the 100 l tank.
Obviously, this is only one trip. I will certainly see if I can increase mileage by driving without cruise especially with headwinds. I tried to control as many of the variables as possible during this trip but still there has to be some ‘human’ and ‘environmental’ effects that impact mileage. I would be interested in hearing what others have to say. Everyone drives differently and with the price of gas, anything that increases mileage is ‘a good thing’.
