The 900 ACE Rotax is an understated and subtle performer, with the heart of a lion. After riding more than 500 aggressive kilometres (310 miles) on some of Quebec’s finest trails, many riders are totally sold on this engine. This review dives deep into the performance, features, and overall experience of the Ski-Doo 900 ACE Rotax engine, providing insights for both casual and touring riders.
Ski-Doo Expedition 600r vs 900ace Long Term Comparison
First Impressions and Performance
From the get-go, this no-fuss engine proved its worth by firing up first try at -32˚ Celsius (-27˚ F). Mind you, one had to listen closely to hear that it was running; it’s that quiet. The 900 ACE Rotax was also quiet on the snow.
After riding for a while, one might begin hearing strange sounds and couldn’t figure out what they were. Suddenly it occurred that for the first time, one was hearing the subliminal noises a sled makes while traveling through the snow - track turning, suspension moving, skis swishing - all sounds usually obscured by engine buzz, but not by the 900.
Coming off a Renegade X 600 ETEC last season, one might start their first ride this winter on the Renegade 900 ACE Rotax in Sport Mode. The first major difference was throttle response. Normally, some thumb fatigue is felt during early season rides while hand muscles re-acclimatize to working the throttle. But there is no work using the 900 ACE lever; it’s light as a feather. Once acclimated to its action, it gave a new ultra smooth dimension to accelerating through the corners.
Acceleration and Torque
The engine is smooth, powerful and linear under acceleration. In sport mode, acceleration is much livelier. It’s ideal for an adrenaline rush. Speaking of acceleration, one may be surprised at the pull on their arms when nailing the throttle in Sport Mode. In this mode, the 900 ACE Rotax is definitely torquey enough to more than satisfy most trail riders.
Even in Standard Mode, while not as torquey, the 900 ACE Rotax provides more than enough oomph for normal trail riding. The standard mode offers lively acceleration with a level of response that is predictable.
The ECO mode is also available and offers slower acceleration, but stronger than expected. Eco Mode is good for loading and unloading from a trailer, maneuvering in and out of gas stations, parking at restaurants and motels, and getting unstuck.
Handling and Suspension
The front suspension, RAS X type with HPG shocks, offers almost 1 inch more travel compared to the RAS 3. It handles very well on the trail and is predictable. One might not feel any swaying.
Fuel Economy and Range
One may be surprised by the fuel economy of this engine. As this was a break in ride, a good measure of fuel economy may not be available as it will be after the first service when all systems go to normal, but it was certainly very acceptable.
Careful fuel records were kept while trail riding 1,078.1 kilometers on two different tours. What matters most is how far one can ride starting with a full 40-litre tank.
The fully loaded Renegade Enduro 900 ACE (tour luggage, Woody’s studs + snowmobile suited, 220-lb person) averaged 310 km per tank. The lighter MXZ 900 ACE got 335 km per tank. By way of comparison, in previous winters on current year Ski-Doo snowmobiles the average was 350 km per tank on a 600 ACE.
Note: These results are based on a specific riding style and load. Results may vary based on individual factors.
Features and Comfort
The snowmobile is equipped with a 7.8″ wide color LCD panoramic display, which offers excellent visibility of the main operating parameters. All the relevant information is displayed, including speed, revolutions per minute, engine temperature, distance travelled, time, etc.
There are 3 choices of display: clear for the day, dark for the evening and automatic. You can also connect to the BRP Connect application, which allows you to have a map of the trails and your position. A cell phone can be placed in the heated case in the glove compartment, plugged into the USB port and that’s it.
On the mirror side, the visibility is excellent towards the back. Visibility is not affected at all. The heated seat is efficient, and the heat can be felt very well even in freezing temperatures.
Finally, on the lighting side, the long-range LED headlights installed by Ski-Doo make a big difference. Riders can easily accumulate kilometers and are not tired at the end of their rides.
Limitations
Any sled powered by the 900 ACE Rotax won’t be the fastest one on the snow. Nor is it intended to be. If you spend most of your time lake running, going full tilt on abandoned rail lines or racing against your buds, this 900 ain’t your cup of tea.
Real-World Performance
Eight of us went on this tour, taking turns riding a Renegade Adrenaline 900 ACE and a GSX LE 900 ACE. My riding buddies gave the 900 ACE a big “thumbs up”. These are experienced snowmobilers, most avid 2-strokers. Each rode for at least half an hour in real life trail conditions where higher-powered sleds set the pace. The 900 ACE impressed everyone by staying right with the pack.
Over three days of hard riding in Quebec, one may never have it to the bar, never run out of juice and never feel underpowered. It's always possible to keep up with those 600’s and 800’s, because all of us were going as fast as was comfortable and safe on those trails and conditions. And believe me, these trails were set up for zippier riding than most other trails any of us will encounter anywhere else, so the 900 ACE Rotax will do just fine in more than 90% of the places you or I will ever ride.
Certainly before trying it, some riders were questioning the viability of the 900 ACE. But after putting almost thousands of kilometres on that engine, it can be confirmed that it will be everything most casual and touring riders ever wanted from a snowmobile engine. It’s efficient, reliable, smooth, and with more than enough power to do the job. Throughout touring, the 900 ACE never under-performed, ran out of power or disappointed anywhere through the entire power band.
Top Speed
To check top speed, the engine was tested on a long, flat rail-trail. The fully loaded, long track Renegade topped out at 137 km/h. Meanwhile, the shorter track MXZ with a lighter load made it to 140 km/h.
Engine Modes
Sport Mode was torque-ier than needed for most trails. Meanwhile, Sport Mode was torque-ier than needed for most trails.
Table: Ski-Doo 900 ACE Rotax Engine Performance
| Attribute | Renegade Enduro 900 ACE | MXZ 900 ACE | 600 ACE (Comparison) |
|---|---|---|---|
| Fuel Tank Range | 310 km | 335 km | 350 km |
| Top Speed (Renegade) | 137 km/h | N/A | N/A |
| Top Speed (MXZ) | N/A | 140 km/h | N/A |
Having racked up more miles on a 900 ACE in several seasons than most other riders in North America, there is no reservation in recommending this engine as the preferred Ski-Doo motor.