What It Was Like Off-Roading An Electric Jeep With A Manual Transmission

I just got back from the Easter Jeep Safari (where I blasphemed in a Ford Bronco Raptor — more on that in a later article). While there, I had the chance to drive Jeep’s EJS concept vehicles, and without a doubt, the most technically interesting was Magneto 3.0, the third iteration of Jeep’s Magneto concept, which debuted a few years back, and which I made fun of in an article titled “The Electric Jeep Wrangler Concept Looks Like It Was Designed By A High School Shop Class.” I think I ticked some folks at Jeep off, but I don’t think I was totally out of line — Magneto is not a production-viable machine, and for Jeep’s first EV debut to be something so primitive felt a little silly given the then-current auto climate. Or maybe I was being a jerk. Regardless, I got to (briefly) drive this concept Jeep off-road, and it was phenomenal. Here’s why.

Okay, let’s just get straight to my “High School Shop Class” dig: The Jeep Wrangler Magneto, especially the version that first debuted in 2021, is a very basic electric vehicle. It does not have a separate drive unit (which integrates a motor and gear reduction into a single housing, sometimes along with power electronics), it doesn’t have a skateboard platform with a flat cabin floor, it doesn’t have a huge battery pack tucked between the axles, and it isn’t aerodynamically optimized to reduce drag. It is an internal combustion engine-powered Jeep Wrangler JL modified, arguably rather crudely, to be electric. Despite this, as I will note in a minute, it’s phenomenal off-road, as I found out when I got to drive the vehicle for the first time.

I said “crudely” modified, because what Jeep has done is essentially just bolt an electric motor to a manual transmission — something that shop classes around the world have been doing since the 1980s, and probably earlier:

The transmission is a Tremec out of a Challenger Hellcat, which is a good thing, because it has to handle up to 850 lb-ft of torque (and 625 horsepower).

Here’s a look at a thick stack of adapter plates between the motor and transmission bell housing:

  

You can see in the image directly above a “SEVCON” DC-DC converter, which takes the lithium ion battery’s high voltage (800 volts, 70 kWh, per Motor Trend) and steps it down to power the vehicle’s 12-volt accessories (like the dash lights, wiper motors, headlights, and so on). You can also see a custom crossmember to hold up that transmission, and in the background are the battery cells, taking the place of the gasoline vehicle’s fuel tank and exhaust:

The image directly above shows that the Wrangler’s four-wheel drive transfer case remains, sending power via driveshafts to the solid front and rear axles. There’s a beefy “Dynatrac 60” up front and a beefier “Dynatrac 80” in the rear, both with 5.38 reductions in their diffs. Wheels are 20-inchers wrapped in 40-inch tires, and spaced away from the body with a three-inch lift.

High-Volume Vehicles With Two Live Axles Will Likely Die Off As The World Goes Electric

Anyway, if it’s so crude, then why does it even matter? Why write about it? Well, it matters because it may be the only live-solid-front-and-rear-axle-equipped electric car ever built by a mainstream automobile manufacturer, and it may stay that way until the end of time. That’s because solid axles — beloved among hardcore off-roaders — have no place in the EV world, as our suspension engineer Huibert Mees has made clear in his article “The Surprising Ways Electric Car Suspensions Are Different Than Gas Car Suspensions: Ask An Engineer.”

Here are the main bits from that article:

You may have noticed that there are no EV’s at the moment with live axles. This may change in the future, but there are very good reasons why live axles are not ideal for EV’s.

The first is that live axles need a drive shaft that moves up and down with the suspension. Unfortunately, this driveshaft runs down the middle of the car in the same place where it would be ideal to package batteries.

Batteries take up a lot of space and are heavy so you want them to be mounted low and as close to the center in the car as possible. Unfortunately, that’s also exactly where the driveshaft is. Having a moving driveshaft would take away too much space for the batteries which would hurt range too much. A perfect example is the new Ford F-150 Lightning. Ford ditched the live axle (shown above) and put in a new independent rear suspension just for the Lightning (see below). I think Ford knew it could never make the Lightning work well enough as an EV without going the extra mile designing a whole new suspension. Believe me, Ford would never have spent that kind of money on the F-150 if it didn’t believe it was absolutely necessary. I think you will see this happen more often as existing vehicles are converted to EV.

Huibert’s piece continues, stating:

The other reason is that a traditional differential with the typical ring and pinion gear — a pairing that turns the power 90 degrees — is not a very efficient beast. The ring and pinion depend on a sliding action between the gears in order to minimize noise, and this adds friction. Friction is an energy loss and EV’s are all about minimizing energy losses so that you get as much range out of a battery charge as possible.

I will say that there are some companies out there developing electric motors that are mounted on a live axle (see below) but as a suspension engineer, I would be very concerned about the increased mass from these motors. Unsprung mass is the enemy of good ride and handling and is the reason live axles are not in use much anymore. Increasing unsprung mass with the addition of an electric motor to the axle would be the wrong way to go, in my opinion.

I don’t think we will see many companies building EV’s with live axles unless they are desperate to get into the EV market with an existing product and they just don’t want to spend the money on a new suspension. I highly doubt the resulting product will be as competitive as it could be.

Though there are some solid axles with motors integrated into the diff housings, and there are some with hub-mounted motors, the reality is that the live front axle is almost certainly going to die with the internal combustion engine, as it just doesn’t make a ton of sense with an EV. Hell, it’s pretty much already dead, other than in the Wrangler and in heavy-duty truck applications. Even the live rear axle alone is likely to start dying off (again, we may see some hub motors like in the Lordstown prototype); remember, when Ford modified its F-150 platform to create the Lightning, it didn’t just clear out the crossmembers to make way for a big battery, it also changed the solid rear axle to independent suspension.

The death of the solid axle is a shame if you love off-roading, because a live axle is brilliant in the most treacherous conditions; the reason for this has to do with roll centers and durability, as Huibert mentioned in his article “Our Suspension Engineer’s Take On The ‘Solid Axle vs Independent Suspension’ Off-Road Debate.” Pair such a superior suspension design with an electric motor and you have something truly magical off-road — something that will likely never exist in production, but that absolutely dominates on the rocks. 

I found this out when I drove Magneto — specifically Magneto 3.0 — for the very first time in Moab last week.

It May Be A Primitive EV, But It’s An Off-Road Beast

To start Magneto, you press in the clutch and then hit the power-on button — just like you would if the vehicle had a gas engine. From there, you can let off the clutch, since there’s no “idle” necessary with an electric motor (with a gasoline engine, you have to turn the engine over to build compression to get combustion — at zero RPM, there’s essentially no torque other than that of the starter motor. An electric motor builds torque to propel your vehicle at zero RPM). Then you simply put the transmission in gear (I like to clutch in when I do this), and tap the accelerator pedal.

My friends at Quadratec get into the “starting”/driving experience in this video:

And here are my friends at TFL showing off the last iteration (2.0) — you can really get an idea for how silent this machine is on the rocks in this video:

Changing the position of your foot on the accelerator pedal of an electric vehicle changes the current sent to the electric motor(s). How the pedal’s position relates to the current output from the battery to the motor (and thus torque output at a given speed) is dependent upon how engineers have calibrated that pedal (via the controller — you can see some of the power electronics in the video above the Quadratec one).

Like with an ICE car, when you change gears, you’re altering how much your motor’s torque is multiplied before it gets to your wheels — and it’s torque at the wheels that affects acceleration/climbing ability. So the gears on Magneto 3.0 behave somewhat like you’d expect them to. A low gear allows you to hold your foot lightly on the pedal, and still crawl up a grade easily at a low speed. To go faster, you have to dip into the pedal further, and though you can go quite fast in first (unlike in an ICE, whose RPM is limited due largely to reasons associated with rotational inertia — also, torque tends to drop at the top end), second gear lets you do that without dipping as far on the pedal. In fact, second gear works fine from a stop to probably highway speeds, though I never drove above about 15 mph.

My shifting was a bit clunky, as matching the motor speed with the wheel speed was tricky, and though an electric motor has less inertia than an internal combustion engine does, slowing it down and speeding it up does come with a bit of a shudder. And trying to get the pedal position just right for a smooth shift is not easy; I often found myself too deep on the pedal, such that when I upshifted, the Jeep would want to take off, forcing me to back off. Maybe I’d have figured it out over time — and certainly it’s something that could have been baked into the software to make it feel smoother — but I found that just stopping the Jeep, then dropping it into first gear when I got to a steep obstacle, was about the only time shifting out of second made any sense.

That first gear is where Magneto shined; what makes this machine so unbelievable off-road is its incredible low-speed control. Truly, it felt like I could pilot this Jeep up a steep grade at 0.2 mph; it was unlike anything I’d ever experienced off-road. Generally, to drive that slowly up a steep grade, even with a Jeep that has a high 70:1 crawl ratio, one has to carefully modulate that throttle based on the change of severity of the slope/obstacle. On most vehicles with lower crawl ratios (which I explain in detail here), one has no choice but to left-foot brake, as the vehicle wants to drive too fast. Wranglers, especially automatics, are a bit better about that, but the fact of the matter is: Torque is dependent upon engine speed, so if you need more torque than you have at the engine speed that corresponds with your desired vehicle speed, you have no choice but to speed up. That can cause you to lose control.

Magneto, which also adds to its low-end torque and beautifully calibrated pedal with a crawl ratio of somewhere around 100 (multiply the 5.38 axle ratio by a ~4.7 first gear ratio by a 4:1 transfer case low range ratio), doesn’t have this issue. It lets you crawl in a way that only a Mercedes Unimog can really understand:

With all that gearing, even driving down a grade at half a mile an hour with your foot off the accelerator means that motor is spinning quite quickly, and offering heaps of regenerative braking. This makes it so that, eve on steep downhill grades, one has to actually press the accelerator pedal to move, allowing for precise speed control even downhill.

So sure, Magneto is a fairly primitive EV, but to combine its silent torque with all that control with all that suspension articulation afforded by the soon-to-be-departed solid axles — it’s just an astonishingly-capable thing of beauty. As an off-roader who has been obsessed with crawl ratios, low-end torque, and Ramp Travel Index scores for over a decade, I’m in awe. And a bit sad that such a contraption will likely never exist on the U.S. market.