A trip to Big Bear from Ontario isn't a long drive on paper, just about an hour and twenty minutes covering roughly 60 miles, but the character of that drive changes completely once you leave the valley floor. The road climbs from Ontario's elevation up past 6,700 feet at the lake, winding through Highway 330 via Running Springs or Highway 38 through Redlands, with tight curves and real elevation change the whole way. Your Forester's Symmetrical AWD system and X-MODE terrain management are built for exactly this kind of trip, but a system that's been sitting unused since your last mountain run deserves a look before you trust it with snow, ice, or a loose gravel pull-off.
The Forester underwent its full redesign for the 2025 model year, and the 2026 model carries that platform into its second year with standard Symmetrical AWD, 8.7 inches of ground clearance on regular trims, and the Wilderness trim's 9.3 inches for owners who want even more margin on rougher terrain. Whichever Forester is in your driveway, a few checks before heading up the mountain go a long way toward making sure the trip goes smoothly.
Why the Climb to Big Bear Is Different From Everyday Driving
Most Ontario-area Forester trips involve flat valley driving, the kind of commuting and errand-running where the AWD system rarely has to work very hard. The drive up to Big Bear is the opposite. Sustained climbing at elevation puts the engine and drivetrain under continuous load in a way a flat commute never does, and the curves on Highway 330 and Highway 18 ask the AWD system to manage traction through corner after corner rather than the occasional turn at an intersection.
Temperature and road surface change quickly once you're above 5,000 feet, especially outside the summer months. Tire chains are required by law on these mountain roads from November 1 through April 30, and conditions can shift from dry pavement to snow or ice within a relatively short stretch of driving. A Forester that handles flawlessly on the way out of Ontario can be navigating a completely different surface by the time it reaches Running Springs or Arrowbear.
What to Check Before You Go
A pre-trip inspection doesn't need to be complicated, but a few specific items matter more for a mountain trip than they would for everyday driving:
- Tire tread depth and condition across all four tires, since Symmetrical AWD depends on consistent rolling circumference between tires to distribute torque correctly, and Subaru's own guidance calls for tread depth variance to stay within 2/32 of an inch across the set
- Tire pressure checked cold, since elevation and temperature changes on the way up can affect readings, and underinflated tires lose grip exactly when the climbing curves need it most
- Brake fluid and pad condition, since sustained mountain descents put more demand on the brakes than flat driving ever does, and a system that's overdue for attention is the wrong thing to discover halfway down Highway 330
- All-wheel drive and X-MODE function, confirmed working correctly rather than assumed, particularly if it's been a while since your last trip into terrain where the system actually had to engage
- Wiper blades and washer fluid, since visibility matters more on a winding mountain road than it does on a flat city street, and worn blades are an easy thing to overlook until you need them
If you're driving a Forester Wilderness, it's also worth confirming the rear differential temperature sensor and the Wilderness-tuned suspension are showing no warning signs, since that trim's added capability assumes those systems are in good working order when you actually put them to use.
Don't Skip Tire Chains If You're Going in Winter
Even with standard AWD and X-MODE, California law requires carrying tire chains on these mountain roads during the designated winter season, and Caltrans can restrict any vehicle from entering a chain control area if it doesn't meet the requirement. AWD helps with traction, but it doesn't exempt your Forester from chain laws, and conditions can change fast enough that having chains in the car, even if you don't expect to need them, is the kind of preparation that costs nothing and occasionally saves a trip.
When a Quick Look Isn't Enough
If your Forester has been pulling slightly to one side, if you've noticed any unusual noise from the rear differential, or if it's simply been a long time since the AWD system was actually checked rather than just assumed to be fine, a proper inspection before a Big Bear trip is worth the time. A technician can verify tread depth variance across all four tires, confirm the AWD system is engaging correctly, and check brake condition in a way that a quick visual look in your own driveway can't fully replicate.
The Subaru-certified service team at Subaru of Ontario, located at 1195 Auto Center Dr, Ontario, CA 91761, can run through a complete pre-trip inspection on your Forester before you head up the mountain. Schedule a quick check, and head into the San Bernardino Mountains knowing your AWD system is ready for whatever the climb brings.