The 2008 Cadillac Trucks SRX came from a period when Cadillac was blending car-like road manners with the taller stance and utility expected from a luxury crossover. That gives this SRX a tire story centered less on vintage-style construction and more on matching the exact front, rear, and package-specific fitment the vehicle was built around. Depending on the sub-model, the 2008 Cadillac Trucks SRX uses one of five primary radial tire sizes across 17-, 18-, and 20-inch rims. Some versions use a staggered front-and-rear setup, while the Sport (AWD) configuration centers on a 20-inch fitment. The key is confirming the exact sub-model and wheel setup before choosing among available radial replacements.
Which Tire Size Is Right for The 2008 Cadillac Trucks SRX
The 2008 Cadillac Trucks SRX uses five primary tire sizes, and the correct one depends on the exact sub-model and whether the vehicle uses a front-and-rear staggered setup. Rim diameter also varies between 17, 18, and 20 inches, so the first step is confirming both the specific SRX configuration and the wheel size currently on the vehicle before selecting tires.
In 255/50R20, the 255 identifies nominal section width in millimeters, 50 is the aspect ratio, R indicates radial construction, and 20 is the rim diameter in inches. This is a modern metric radial fitment used on the 2008 Cadillac Trucks SRX Sport (AWD), pairing a lower-profile sidewall with a larger wheel diameter than the other SRX configurations covered here. Buyers considering this size should confirm that the vehicle still has its 20-inch wheel setup, since moving between rim diameters is not a tire-only change and affects the entire fitment decision.
The size 235/65R17 uses a 235-millimeter nominal section width, a 65-series aspect ratio, radial construction, and a 17-inch rim. On the 2008 Cadillac Trucks SRX, this size serves as a front fitment for the V6 Front configuration and reflects a taller sidewall profile than the 18- and 20-inch alternatives. That makes it important to treat this as a position-specific tire choice rather than a general SRX size, especially on vehicles that use different front and rear tire widths.
A 255/60R17 tire combines a 255-millimeter nominal section width with a 60-series profile, radial construction, and a 17-inch rim diameter. On the 2008 Cadillac Trucks SRX, this size appears as a rear fitment on the V6 Rear configuration, making it part of a staggered arrangement rather than a universal four-corner setup. The practical takeaway is to verify axle position before ordering, because the wider 255-section rear size serves a different role than the narrower 235-section front tire on 17-inch-equipped versions.
Fit(s): V6 w/Luxury Performance Pkg. Front and V8 Front
Construction: Radial|Rim: 18 in
In 235/60R18, the 235 is the nominal section width in millimeters, 60 is the aspect ratio, R marks radial construction, and 18 identifies the wheel diameter in inches. This size is used as a front fitment on SRX versions equipped with the Luxury Performance package and on V8 Front applications, so it belongs to specific 18-inch staggered setups. Buyers should confirm that the vehicle still carries the correct 18-inch front wheels and has not been altered to a square tire arrangement before choosing this size.
Fit(s): V6 w/Luxury Performance Pkg. Rear and V8 Rear
Construction: Radial|Rim: 18 in
The size code 255/55R18 indicates a 255-millimeter nominal section width, a 55-series profile, radial construction, and an 18-inch rim. On the 2008 Cadillac Trucks SRX, it serves as the rear fitment for V6 w/Luxury Performance Pkg. Rear and V8 Rear configurations, pairing with a narrower 235/60R18 tire up front. That means this size should be chosen with rear-position fitment in mind, and owners should check that both wheel diameter and front-to-rear stagger remain consistent with the vehicle's current setup.
Tire fitment on the 2008 Cadillac Trucks SRX varies by sub-model, wheel package, and in some cases by front versus rear position. Checking the exact SRX configuration matters here because the vehicle uses multiple rim diameters and several staggered fitment combinations.
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2008 Cadillac Trucks SRX Sport (AWD)
The 2008 Cadillac Trucks SRX Sport (AWD) uses a dedicated 20-inch radial fitment rather than the 17- or 18-inch combinations found elsewhere in the SRX range. Tire selection starts with confirming that the vehicle still has its Sport wheel setup, since appearance and fitment decisions here revolve around that larger-diameter package.
The 2008 Cadillac Trucks SRX V6 Front uses a 17-inch front radial size that works as part of a staggered front-and-rear arrangement. Tire selection should account for axle position first, because the matching rear fitment uses a different width and size rather than the same tire at all four corners.
The 2008 Cadillac Trucks SRX V6 Rear carries the wider 17-inch rear tire in the staggered V6 setup. Choosing the right replacement means confirming that the rear axle still uses the original size pairing and that the current wheels have not been changed to a different diameter or square configuration.
2008 Cadillac Trucks SRX V6 w/Luxury Performance Pkg. Front
The 2008 Cadillac Trucks SRX V6 w/Luxury Performance Pkg. Front uses an 18-inch front radial size matched to a different rear tire. That makes wheel-package confirmation especially important, since the correct front replacement depends on keeping the intended 18-inch staggered layout in place.
The 2008 Cadillac Trucks SRX V6 w/Luxury Performance Pkg. Rear uses the wider 18-inch rear tire in its staggered setup. Tire selection should focus on rear-position fitment, with attention to maintaining the correct front-to-rear pairing rather than treating this as a universal SRX size.
The 2008 Cadillac Trucks SRX V8 Front uses the same 18-inch front radial size found on the V6 Luxury Performance package front application. That keeps tire choice straightforward once the front axle and wheel diameter are confirmed, but it remains important to match it to the proper rear size.
The 2008 Cadillac Trucks SRX V8 Rear uses the corresponding wider 18-inch rear radial fitment. Selecting tires for this application means confirming rear axle placement and preserving the staggered relationship with the front tire size already used on the vehicle.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Frequently Asked Questions
The most common tire questions for the 2008 Cadillac Trucks SRX center on identifying the exact sub-model, matching front and rear sizes correctly, and confirming wheel diameter before replacement. Buyers also tend to ask about staggered fitment, appearance consistency, and what to inspect before putting an SRX back into regular road use.
Tire Size & Fitment
What tire size fits a 2008 Cadillac Trucks SRX?
The 2008 Cadillac Trucks SRX uses five primary radial tire sizes: 255/50R20, 235/65R17, 255/60R17, 235/60R18, and 255/55R18. The correct size depends on the exact SRX sub-model, and several versions use staggered fitment with one size on the front and a different size on the rear.
The practical first step is identifying the exact SRX configuration and wheel diameter before choosing tires. A V6 or V8 setup with separate front and rear sizes should not be treated like a four-matching-tire application, and a Sport (AWD) model on 20-inch wheels belongs to a different fitment path than the 17- and 18-inch versions.
What size rim does a 2008 Cadillac Trucks SRX use?
The 2008 Cadillac Trucks SRX uses 17-inch, 18-inch, or 20-inch rims, depending on the sub-model. The 17-inch sizes are 235/65R17 and 255/60R17, the 18-inch sizes are 235/60R18 and 255/55R18, and the Sport (AWD) application uses 255/50R20 on a 20-inch rim.
Rim diameter is the first fitment point to confirm because it cannot be changed with tire size alone. Checking the wheel currently on the vehicle matters even more on an SRX that may have seen wheel upgrades, take-off wheel swaps, or package changes over time, especially when the vehicle uses different front and rear tire sizes.
Why does the 2008 Cadillac Trucks SRX have more than one tire size?
The 2008 Cadillac Trucks SRX has more than one tire size because fitment changes by sub-model, package, and axle position. Some versions use 17-inch wheels, others use 18-inch or 20-inch wheels, and several applications are staggered, meaning the front and rear tires are intentionally different sizes.
That affects replacement strategy because the tire decision starts with vehicle configuration, not just the model name. An owner should verify whether the SRX is a Sport (AWD), a V6 staggered 17-inch setup, or an 18-inch V6 Luxury Performance or V8 arrangement, then confirm that the wheels on the vehicle still match that intended layout.
Choosing the Right Tire
What should I consider when choosing a 2008 Cadillac Trucks SRX tire?
Start with the exact tire size required for the SRX sub-model and axle position, since this vehicle uses several distinct radial sizes and multiple rim diameters. On many 2008 Cadillac Trucks SRX applications, the front and rear tires are not the same, so matching the correct size to the correct end of the vehicle matters first.
After size is confirmed, compare the tire's intended use with the vehicle's current setup. Wheel diameter, any prior modifications, and whether the SRX still carries its original staggered arrangement all influence the final choice, and appearance consistency front to rear is worth checking when replacing only one axle pair instead of all four tires.
How do I choose between the available 17-inch and 18-inch tire setups for a 2008 Cadillac Trucks SRX?
A 2008 Cadillac Trucks SRX should use the tire setup that matches its actual wheel diameter and sub-model, not whichever size appears closest on paper. The 17-inch fitments pair 235/65R17 front with 255/60R17 rear on one V6 arrangement, while the 18-inch fitments use 235/60R18 front and 255/55R18 rear on specific V6 package and V8 applications.
The right comparison is between the vehicle's current wheel package and its intended front-to-rear size relationship. Owners should inspect the wheels already installed, confirm the axle position of each tire being replaced, and avoid mixing a 17-inch fitment strategy with an 18-inch one unless the entire wheel-and-tire package has been deliberately changed and rechecked.
How do I choose between the available 2008 Cadillac Trucks SRX tire sizes if the vehicle has been changed?
Once a 2008 Cadillac Trucks SRX has had wheel or tire changes, the correct replacement size is determined by the vehicle's actual current setup rather than by model name alone. The covered SRX configurations span 17-, 18-, and 20-inch rims, and several use staggered front-and-rear sizing, so a modified vehicle needs to be checked carefully.
A good starting point is verifying the size molded on each existing tire and confirming the wheel diameter at each axle. From there, compare whether the vehicle still uses a square setup or a staggered one, and inspect clearance at the fenders and steering components before repeating the current fitment or moving back toward an original-style package.
Restoration & Appearance
Does correct tire fitment matter for a 2008 Cadillac Trucks SRX restoration?
Yes, correct tire fitment matters on a 2008 Cadillac Trucks SRX restoration because wheel diameter, front-to-rear size relationship, and overall stance are all part of how the vehicle presents. An SRX restored with the wrong axle pairing or the wrong rim diameter can look out of proportion even before any road-use issues appear.
Appearance-oriented buyers should first decide whether the goal is returning the SRX to its original-style package layout or preserving a long-standing later modification. Once that is clear, matching the correct 17-, 18-, or 20-inch fitment and keeping the intended staggered setup where applicable will do more for visual accuracy than choosing a random replacement with a similar tread look.
How does tire size affect the appearance of a restored 2008 Cadillac Trucks SRX?
Tire size has a visible effect on the appearance of a restored 2008 Cadillac Trucks SRX because the model was offered with several wheel diameters and different sidewall proportions. A 20-inch Sport (AWD) setup presents differently from a 17-inch V6 arrangement, and the 18-inch package has its own balance of wheel presence and sidewall height.
The most useful approach is to match the restoration goal to the correct package-style fitment rather than choosing by diameter alone. A staggered front-and-rear setup should also be preserved when the vehicle calls for it, since maintaining that relationship helps keep the SRX's intended visual stance instead of flattening the look with mismatched or substitute sizes.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2008 Cadillac Trucks SRX?
Yes, modifications can affect tire fitment on a 2008 Cadillac Trucks SRX. Wheel swaps, suspension changes, lowering, alignment changes, or a move from a staggered setup to a square one can all change what size tire the vehicle can use safely and cleanly.
That matters because the SRX already spans 17-, 18-, and 20-inch fitments from the factory. Any owner working with a modified vehicle should confirm wheel diameter, tire size at each axle, and clearance during steering and suspension movement before repeating the existing setup or returning to one of the original-style SRX size combinations.
What should I inspect before driving a 2008 Cadillac Trucks SRX on new tires?
Before driving a 2008 Cadillac Trucks SRX on new tires, inspect wheel condition, confirm the correct size at each axle, and make sure inflation is set properly for the tires installed. It is also worth checking for uneven wear signs, visible suspension issues, and any rubbing points that could show up with the front wheels turned.
A short test drive followed by a recheck can catch problems early. Listen for rubbing, note any pull or vibration, and look again at inner-fender and suspension clearance, especially on staggered SRX setups or vehicles with replacement wheels, since front and rear fitment differences leave less room for guessing.
What should I check before a longer drive in a 2008 Cadillac Trucks SRX?
Before a longer drive in a 2008 Cadillac Trucks SRX, confirm that all four tires match the intended front and rear sizes for the vehicle's setup and inspect them for cuts, cracking, bulges, and irregular tread wear. Tire pressure should also be checked when the tires are cold, and the wheels should be examined for damage or looseness.
A longer trip places more importance on consistency across the entire package. On an SRX with staggered fitment, verify that front tires are not accidentally installed on the rear or vice versa, and take a moment to check for vibration, brake pull, or contact marks around the wheel wells before committing to extended highway use.
