Shifting gears can extend the life of your tranny.
Now that transmissions have so many gears, there is a lot more shifting going on during both towing and solo operations. Some people think that if the tow vehicle has to shift in hilly terrain, then they must need more power. To them, it is as if shifting gears means that the engine is admitting defeat. The error in this thinking is that if your tow vehicle is geared to tow easily in its tallest gear, then it is turning far faster than it needs to when not towing. So, the intelligent way to configure a tow vehicle is to have the taller gears suitable for solo driving to maximize solo fuel economy, and remaining gears would be used for towing.
Older automatic transmissions wear a little bit each time they shift. Twenty-five years ago, if you needed to downshift from third to second on a hill, you would let up on the gas a little, make the shift, and then step on the throttle again. If you got it right you could achieve a pretty smooth shift. Today, the cars computers do all that for you – when you shift gears the fuel to the motor is cut back for less than a second, the shift is made in the blink of an eye, and the power is re-applied before you know this has happened. This eliminates the strain on the transmission and driveline that shifting used to create. So, the bottom line is that shifting gears is ok and totally normal for the vehicle.
The other neat thing that some vehicles have today is paddle shifters on the steering wheel that let you manually shift the car if you want to. With some of these, you have almost complete control of the transmission with the paddles. Think of it as a very smooth manual transmission without the clutch. I say almost as the transmission still has safeguards built-in: it won’t let you over-rev the engine with too aggressive a downshift, and it won’t let you stall if you forget to downshift as you come to a stop – but otherwise, on the highway you can select fifth gear and it will stay in fifth. This is how the ZF transmission in the Jag and 300 works, as well as many other vehicles.
Our Jeep Cherokee (not a Grand Cherokee) also has a ZF transmission, but this one is a front-drive version instead of the rear drive model in the 300. It has 9 speeds instead of 8. The car is made by the same company, and the transmissions are both ZF’s, but they have very different tuning. The Jeep does not have paddles, but you can shift manually just by moving the shifter front to rear in manual mode. What is different is that the manual mode on the Jeep just limits the top gear. So, if you put it in fifth gear, it will still downshift to lower gears if you press the gas pedal hard enough. I prefer the complete control of the 300 system, but I am sure others don’t want to have to think about it.
Towing in the Rockies
I just returned from a trip where I towed a 28’ Lance travel trailer from Los Angeles to our home in South-Central Ontario. We towed through the Colorado Rockies, so I had plenty of opportunity to get to know the Jeep’s transmission characteristics. This is a spectacular route – Interstate 70 through Utah and Colorado is a very scenic drive through an amazing variety of landscapes, everything from red rocks in deep canyons to high desert plateaus and 11,000 foot passes through the Rockies.
The Jeep has a 3.2 Litre V6 engine producing 271 horsepower and 239 pounds of torque. The Cherokee is a compact SUV intended to compete the VW Tiguan, Ford Escape etc. but it is a more capable vehicle than these, with a stronger chassis and V6 vs 4 cylinder motors. The Jeep weighs more than 4000 pounds, the body structure is nice and solid, and while it is not as quiet inside as a Chrysler 300, it does a pretty good job of keeping you comfortable on a 4000-kilometer drive. If you buy a Cherokee – even if you have no plans to tow with it – get the towing package because the gear ratio is much better suited to the 9-speed transmission. Even with the tow package 9th gear is rarely used in solo driving.
Getting back to the transmission… you may ask: if you cannot lock the transmission into a gear why would you ever bother to manually shift it? You could tow with the Jeep and just leave it in drive, and if you have the cruise control set, it will automatically downshift to control your speed on down grades and most of the time it will choose the correct gear for pulling… but where the system is limited is that it cannot see the road ahead, and sometimes it will rev the engine very high to maintain speed. This won’t bother the motor, but it sure uses more fuel. So, on a two-lane 7% downgrade, the transmission might be holding you nicely at 100 km/h, but it can’t see the 60 KPH turn coming up that you want to slow for. Shifting the tranny yourself, you would pull it down a gear and keep the speed lower. Similarly, when climbing a grade, the Jeep left to its own devices will be running 5500-6000 rpm to maintain speed. When I shifted according to my driving instincts, I found it climbed nicely at 3700-4000 RPM.
So, running on the level at 105 KPH the Jeep would tow in fifth gear at 2700 RPM. On most grades it climbs at 100 KPH in 4th gear at 3800 RPM, and on some of the steeper grades it climbed in 3rd gear at 80 KPH at 4000 RPM, and on the two tallest climbs in Colorado, which are 11,000 feet, it used second gear at 60 KPH with lots of reserve at 4000 RPM. In first gear, the Jeep will run out of traction before it ever runs out of power.
Some people think that slowing to 60 KPH on a hill means you don’t have enough power, but these are two of the most challenging hills in the entire interstate highway system. I was passing all the loaded transports, and even the empty transports were not going much faster than I was. All together, on a 4000-kilometer trip, slowing for hills only added about 30 minutes to the driving time – or 2 hours less than the traffic jam that getting out of LA added to our route.
Towing the Lance 275
The trailer we towed on this trip was a Lance 275, their second-largest model.
When the “Lite” trailer concept was first introduced in the mid 1990’s the formula was pretty straightforward:
1.) Build a laminated fiberglass trailer, use light weight laminated floor, roof and end walls.
2.) Give it a radically sloped nose.
3.) Keep the overall height and centre of gravity low for reduced drag and stable handling with independent torsion axle suspension.
Pretty logical and straightforward, and for many years there were several companies building using this philosophy. Gradually, however, the expensive torsion axles were replaced with leaf springs, the height of the trailer became taller to accommodate floor-level slide-outs, and the laminated roofs were replaced with press wood on wood rafters. Today, most so-called “Lite” trailers are light in name only.
Lance has been in business since 1965, building truck campers. Due to the tall centre of gravity and balance issues, truck campers by necessity are the most weight-sensitive RVs… they also demand a very effective use of space. Truck camper sales are not quite as brisk as they once were, so, fortunately for us, Lance turned their considerable experience towards building a true Lite trailer. The Lance is about the only product out there that follows the complete formula. They have even improved upon the earlier Lite trailers by using composite materials and Lite ply interior cabinetry.
Aerodynamically, the Lance tows as easily as the narrower Vista Cruiser but it is more stable due to the wider track, lower centre of gravity and independent suspension.
Traveling through eastern Colorado and Kansas we had huge winds that varied from rear corner cross winds to full on cross winds with gusts over 90 kilometers per hour. We did not see another RV on the road the entire day and many of the transports (I would guess empty ones) were parked. The Lance handled better than any other flat wall trailer I have towed. In Kansas, nasty tumble- weeds were blowing across the highway and while I avoided many of them, a few made contact with the Jeep or the Lance. My wife commented that had we been driving the Jag with an Airstream, we would likely be pulled over somewhere so the Tumbleweeds wouldn’t get us.
One other thing that Lance has well done is that their initial quality is excellent. We used this trailer for two weeks straight off the assembly line. We found one plumbing fitting that needed to be tightened after a few days, and the water pump rattled, but other than that I could not find another thing to put on a PDI list. If you would like an impeccably finished well-built RV that tows great then the Lance is well worth a look, it is a great midway step between a typical trailer and an Airstream.