Home / Equipment / Tacoma / 255/85 R16 Tires

The Expedition's West 2004 Tacoma on the White Rim Trail, Canyonlands Utah
Fitting the BFG 255/85 R16
Vendor:

Manufacturer:
BF Goodrich

Sponsor:
Big-O Tires, Arizona

Vehicle: Expeditions West: 2004 Toyota Tacoma Double Cab TRD
Cost:

Retail: $1,290 for all 6 tires and wheels, mounted/balanced
* Pricing subject to change, contact vendor

Weight :

27lb. increase per tire and wheel over stock.
Unsprung weight increased by 108lbs.
Available Payload decreased by 27lbs.

Installation Difficulty | Time required Difficult | several hours
Specialty tools required None
Expeditions West Product Rating
(Rating definitions)
Quality Capability
Durability Value
Reliability N/A Expedition Rating
Overall Rating

Tire Selection for Expedition Travel

The Expedition's West Tacoma is not a "rock crawler", and was designed for remote, rugged expedition travel in Mexico and throughout the Southwest. I wanted a tire with good load carrying capacity, sidewall strength, tall section height for ground clearance, and mud traction for our planned trips to the jungles of Guatemala and the outback of the Yukon Territory and Alaska.

My research led me to the position that a tall, yet narrow tire would be the best solution for my needs and provide the greatest performance in the terrain I travel. To read the details of my research on tire selection and the influence of tread width on traction, please consult my recent Technical Document on the subject:Narrow tire benefits

 
Installation of the 255/85 R16 on a 2004 Tacoma Double Cab

 

Summary

I chose this tire size even before I made my final vehicle selection. The Expedition's West Tacoma is the first documented to run this size tire. The 255/85 R16 (33.4x10.5 as measured) tire provides several performance advantages over the 33x12.5 or 285/75 R16 tire.

Tire Details:

BF Goodrich Mud terrain KM, LT 255/85 R16/D 119Q (note: BFG site lists height as 33.3" on a 7" rim)

Wheel Details:

American Racing 797 16x8, 4" backspacing

Words of caution:
I will start by saying the 255/85 is a large tire for the Tacoma with IFS and and full travel (no lowering of bumpstops, etc.), and is not a bolt-on endeavor. These tires measure 33.4" tall, and are much taller than the typical 33. The picture on the right shows the BFG 255/85 R16 next to a BFG 33x10.5 R15. There is a 1.3" difference in height between the two tires.

So what does that mean? There are three critical items that need to be addressed when installing these tires.
1. Fenderwell clearancing
2. Relocation of the rear axle
3. Regearing of the differentials

 

How Much Lift? None is required to fit these tires on a Tacoma.

It is a common misconception that "lifting" the vehicle allows for fitment of larger tires. In reality, it is the Increased fender clearance/trimming, wheel offset and relocation of the bumpstops that allows for the larger tires. The key is to fit as large a tire possible for ground clearance, while retaining maximum suspension travel for performance. Since the goal here is not to build a rock crawler, suspension performance takes a priority over tire height. I did change the suspension on the truck, which resulted in an increased suspension height of 1.5" in the front and 2" in the rear (vehicle at GVWR). The picture at right shows the tires installed on the vehicle at stock height. As mentioned above, it is necessary to do heavy trimming, relocate the rear axle and use the correct offset wheel.

Picture taken post trimming, pre lift.

Suspension Selected:

Components of this suspension won the Baja 1000 in 2004, and is of the highest build and ride quality.

Front: Donahoe standard length coils, set to 1.5" lift, stock bumpstop height. These coil-over's allow full stock travel with a 30% increase in spring rate, which helps to control the heavy tires and wheels. Rebound control is excellent, compression is somewhat firm, but secure. Swaybar is removed on this vehicle to allow full articulation.

Rear: Deaver custom 10 leaf pack with .5" center pin adjustment to midline of truck. Expedition load height: 1.75-2.00". The rear suspension is critical to fitting these tires, as the center pin MUST be moved forward .5" to allow full compression or the tire will destroy the rear of the wheelwell. Shocks are Bilstein 5100, extended length.

All components are available from Demello Off-road

Fender Trimming

I drove the truck for a few days with the larger tires installed to leave "witness marks" of where the tires rubbed. The rubbing is most evident on the rear splash guard of the front wheelwell. The tires also rub at the rear of the fender flare of the rear wheelwell.

The first step is to trim the fender skirt (slash guard) along the witness marks, which will expose the seam weld (also referred to as a pinch weld). I used a Dremel tool with a roto attachment to trim the plastic; though a sharp razor is also effective.
Start by bending the lower pinch weld proximal to the midline of the truck
Most that perform this modification just hammer the extra material flat. I chose to cut it off completely. Neither way is "better", but cutting the extra material off is a little cleaner.
The next step is to start the main pinch weld bend using a crescent or similar. Follow up by flattening the weld against the firewall using a large hammer.
Also flatten the rolled upper flange and address any other areas that show tire contact. I needed to make several small corrections to the area left of the upper rolled flange.
I finished the job by painting the areas hammered, and then undercoating the wheelwell.
The next critical step is to replace all of the fender flare mounting bolts (the black ones with the raised hex head) with fender washers and screws. This arrangement sits nearly flush with the flare, reducing contact with the tires lugs.
The first step is to ID chamfer all of the 3/16ID x 1" fender washers. This will allow the bevel headed screws to sit deep in the washers surface, minimizing the overall height.
This shows the bevel head screw sitting in the chamfer.
Rear Wheelwell Adjustments

For rear tire fitment the most critical adjustment is to center the axle in the wheelwell. This can be accomplished by replacing the springs with an engineered solution like Deaver, or use a .5" lift block with repositioned pin location.

After centering the axle, the fenders need to be trimmed along the wear marks and the hex bolts replaced with the fender washers and screws.

The tires still rub slightly under full compression, but have not caused any damage.

Impressions

These tires provide improved clearance and traction over a 33x12.5 or 285/75 R16, while allowing fitment with full suspension travel and minimal lift. The tires diameter requires an axle gearing change to maintain highway performance. I have used these tires successfully now for over 10 months and nearly 8,000 miles (all off-road or en route to trails).

Final Clearance Measurements at the rear axle (all tires near new, at 30psi):

Stock 265/70 R16 (baseline): 9 7/16"
285/75 R16 Geolander II's: 10 1/2"
255/85 R16 BFG MT/KM: 10 3/4"


Final tests included a fitment verification on a 23 degree travel ramp. Only minor rubbing was still evident, with full suspension compression to the factory bumpstops. The score was 660.

Acceleration (0-60):
Stock- 10.6 seconds
After installing tires: 13.3 seconds
Note: Axle gearing not changed, speedometer adjusted to dia.

Interior Noise DB:
Stock: 65.4
After Installing Tires: 67

Questions / Comments?