[bredsj]

I've gleaned some interesting information from this discussion forum!

I've got a GLX 3.2 DiD 2006 Model that came out with Yokohama Geolanders 235x80xR16 rims and tyres. I bought the vehicle as a demo model from the dealership in Hatfield. They fitted mags with the original tyres and I got hold of the old steel rims to be used as backup.

I've now also downloaded the specs for the vehicle and see that the standard tyre sizes are supposed to be 265x65xR17.

The above makes me a bit confused especially considring the very valuable information gleaned from this site!

I need to replace the Yokohamas now as they have done 62000km already, maybe I can sqeeze another 5000km.

The question is, WHAT SIZE?? Should I fit the 265 I'll gain 17mm clearance, but the the torque story comes into play?

I'll appreciate a reply.

[Gerrit Loubser]

bredsj, the GLX came with 235/80R16 tyres as you said and definitely not with 265/65R17 tyres. The latter tyre size are for the GLS model. By the way, there is almost no diameter difference between those two sizes so you won't get any lift going from 235/80R16 (nominal diameter 30.8") to 265/65R17 (nominal diameter 30.6").

The problem is that your steel rims are 16 x 6JJ size, i.e. only 6" wide. Most tyres that are wider than 235mm nominal width have to be fitted to wider rims. What size are your alloy rims?

[Bigwill]

The GLX came out with the 235/80x16 tyres on steel rims. These steel rims are narrower (7 inch only) than the standard mags on the Paj. So they transferred the tyres to the wider mags. You will probaly note that the tyres are not ballooning much on the new mags. Pajero's with mags (GLS) have 265/70x16 tyres and that is what I suggest you fit. The rolling diameter of both these tyre sizes should be the same and I doubt if there will be any clearance advantages on either.

[Gerrit Loubser]

No, the steel rims are definitely 16 x 6JJ (i.e. 6" wide). The original alloy rims (up to 2003 in SA) were 16 x 7JJ (i.e. 7" wide) and the later alloys were 17 x 7.5JJ.

If you could get hold of a set of genuine 16" Pajero alloy rims, it would probably be ideal, but perhaps you could use the alloys that you have.

[bredsj]

Thanks guys, I'll go with the 265/70x16

[bredsj]

The problem is that your steel rims are 16 x 6JJ size, i.e. only 6" wide. Most tyres that are wider than 235mm nominal width have to be fitted to wider rims. What size are your alloy rims?

I measured the alloy rims to be 200mm so I assume they will work with the 265x65x16?

[bredsj]

[quote="Gerrit Loubser"]bredsj, the GLX came with 235/80R16 tyres as you said and definitely not with 265/65R17 tyres. The latter tyre size are for the GLS model. By the way, there is almost no diameter difference between those two sizes so you won't get any lift going from 235/80R16 (nominal diameter 30.8") to 265/65R17 (nominal diameter 30.6").
quote]

I am a novice at these calculations but:

265/65R17 = 17x25 + 0.65x265 = 597mm
235/80R16 = 16x25 + 0.8x235 = 588mm

Is this wrong?

[Bigwill]

Use the tyre size calculator on this site to compare the different sizes.
http://www.powerdog.com/tiresize.cgi
They are all within 0.8% on rolling diameter.

[Gerrit Loubser]

bredsj, you are on the right track, but you are mixing radius and diameter up. The ground clearance is related to the tyre radius (and obviously to the diameter as well), but you are calculating a hybrid dimension by adding the entire rim diameter to the tyre height on one side, if that makes any sense.

The nominal radius is calculated as follows:

265/65R17: 265 x 0.65 + (17 x 25.4)/2 = 388.15mm
235/80R16: 235 x 0.8 + (16 x 25.4)/2 = 391.2mm

Of course, the diameters can be calculated along similar lines:

265/65R17: 2 x 265 x 0.65 + (17 x 25.4) = 776.3mm
235/80R16: 2 x 235 x 0.8 + (16 x 25.4) = 782.4mm

Where on the rim did you measure the 200mm width? The rim width that is quoted in the rim designation must be measured in between the flanges where the tyre bead seats. If your rim was measured in this way, it is 7.8" wide and will be perfect for 245/75R16 or 265/70R16 tyres, both of which have very close to your original diameter. You could also have a look at 265/75R16 tyres, but they are taller than standard, so make sure you understand the implications that has on the ability of the transmission to keep the torque converter locked for maximum efficiency. There might be some information on the rim stating the rim size (e.g. 16 x 7J or 16 x 7.5JJ).

[bredsj]

bredsj, you are on the right track, but you are mixing radius and diameter up. The ground clearance is related to the tyre radius (and obviously to the diameter as well), but you are calculating a hybrid dimension by adding the entire rim diameter to the tyre height on one side, if that makes any sense.

The nominal radius is calculated as follows:

265/65R17: 265 x 0.65 + (17 x 25.4)/2 = 388.15mm
235/80R16: 235 x 0.8 + (16 x 25.4)/2 = 391.2mm

Of course, the diameters can be calculated along similar lines:

265/65R17: 2 x 265 x 0.65 + (17 x 25.4) = 776.3mm
235/80R16: 2 x 235 x 0.8 + (16 x 25.4) = 782.4mm

Where on the rim did you measure the 200mm width? The rim width that is quoted in the rim designation must be measured in between the flanges where the tyre bead seats. If your rim was measured in this way, it is 7.8" wide and will be perfect for 245/75R16 or 265/70R16 tyres, both of which have very close to your original diameter. You could also have a look at 265/75R16 tyres, but they are taller than standard, so make sure you understand the implications that has on the ability of the transmission to keep the torque converter locked for maximum efficiency. There might be some information on the rim stating the rim size (e.g. 16 x 7J or 16 x 7.5JJ).

Slaan my met 'n pap snoek! Now I know!

I measured the outside-outside flange dimension. I've got an axtra alloy rim as I want to make a 2nd spare, the size is given inside the rim as 16x7JJ.