Originally Posted by billt460
If you don't mind my asking, why are your engines revving so high? I know trucks tend to be geared a bit lower than cars, but my 2018 Toyota Camry 2.5 turns right around 2,000 RPM at 75-80 MPH. My 2015 Jeep Grand Cherokee with a towing package revs even lower than that. For me to get either of them revving that high on the highway, I would be running well over 100 MPH in top gear. Have you changed the rear end ratio on your trucks?
The gear ratio on the automatic V6 Tacoma is 3.91 and the tire diameter is about 30.5" depending on your option package. The curb weight of an empty Tacoma is about 4400 lbs. All of this makes it impossible to compare against a Camry. However the real issue is the 3.5L Atkinson cycle engine. It develops insufficient torque at lower RPM for the vehicle to hold a higher gear in anything but the flattest and windless of terrain. I am able to stay in 6th only on perfectly flat sections of highway. In 6th I am turning about 1750 RPM at my normal highway speed (65 MPH). At the slightest grade and certainly in hilly terrain the transmission downshifts to 5 and then pretty much to 4 immediately after that so I am now at a touch over 3000 RPM for any hilly / graded sections of the road. We have a road in my neck of the woods called the Coquihalla, it is a high speed (120 kph -> 75 MPH) mountainous road and my Tacoma will drop to 3rd on many sections (5000 RPM) for sustained periods (15 minutes). This poor low end torque curve / high revving powertrain took a long time for me to get accustomed to coming from GM V8 trucks and I still am not comfortable with the number of shift cycles the Tacoma transmission performs in hilly terrain (I manually select lower gears in hilly terrain to avoid hunting) but it is what it is. All of this might sound gloomy but it is far from gloomy for me as my Tacoma utterly cleans up in fuel economy which is exactly what I wanted. My wife's daily city commute figures are about 26 MPG (imperial so 21.5 US MPG) and on a highway trip we get about 29 MPG (imperial so 24 MPG US). I have towed 6200lbs of landscaping material with the vehicle with no issue, albeit at a higher RPM than my GM trucks, but no harm. We needed a truck that was more a grocery getter than work / trailer hauler but still need to occasionally haul 6000 lb loads. Apart from the hunting of the transmission I am happy with the Atkinson powertrain combination.
Oh, by the way, I use 0w20 year round and would use that even hauling 6200 lbs across North America.
