ooo you wagon drivers, us utes or Defers without alloys have 7.5x16, which = 31"Quote:
Originally Posted by Drover
who's 33 are you going with.
Printable View
ooo you wagon drivers, us utes or Defers without alloys have 7.5x16, which = 31"Quote:
Originally Posted by Drover
who's 33 are you going with.
yeh 1st is out there on it's own, but travelling at 4klm for 50klm is no good either. Second is an awesome gear for crawling along in low.Quote:
Originally Posted by PAT303
It seemed to all of us LR have specked there vehicles very closely over the years regarding power, talk, and gear ratios. I presume since they all run the same transfer box this is partly why.
A puma donk for all it engineering and latest fuel delivery is no more economical, or not much more power than a TD5, or TDi.
In fact the puma was the one using more fuel than the others, maybe a bit heavier vehicle, maybe the air con on all the time.
Jason, interesting comment on 7.5R16's = 31". I have a set of 7.5R16's and 31x10.5R15's and the 7.5's are about 1.5 - 2" bigger in diameter than the 31". But that's just measuring them laying on the driveway.
Question guys - how do the 33's affect fuel economy compared to standard diameters? I've read that wider tyres also reduce economy quite a bit. Also, forgive my ignorance but what's the pyro?
cheers Gerald
It is hard to tell about the fuel economy because the speedo changes when you up in tyre size which throws out the distance travelled per tank. I havn't noticed any dramatic change though. But, just going by experience, in a standard tdi, I found I would be back to 4th earlier on some hills, but the overall improvement by going to 33's for outweighs this. As someone posted earlier they bring the engine rpm at 95 - 100km/hr down making for a much more enjoyable time on the highway.
I did however fit the maxi-drive 30% reduction gearset into the transfer case because I didn't want to lose any low range and the transfer case needed overhauling anyway. First low would seem to be on par with the Puma 130.
Cheers, Martin
Drover... Defer with 285's pictured...
Sorry, but I think the 7,50x16" are 32" . The 31" are the 7.00x16".
Leaning toward Mickey Thompson Baja MTZ's but BFG KM2's are also under consideration.Quote:
Originally Posted by newhue
I have got quotes for KM2's - $350 ad Baja MTZ's - $359.
Price is much the same, any opinions on these brands/tyres ?
Despite the maths, 7.50s are 32".Quote:
Originally Posted by newhue
It can also depend on the manufacturer.Quote:
Originally Posted by isuzurover
When I bought the 130 it had half worn XZL's on the back and near new 235/85 Bridgey MT's on the front and from what I can remember there was something like a 3/4" difference in OD.
I did measure it at the time but it was ten years ago now.
The t/case fluid was a lovely colour and odour too :o
Drover - if you go with the 285/75R16 you might not get them on the 16 x 7" rim. I was told by Bob Jane that the 255/85R16's are just on perfect for the 7" rim and i was told by others that the 265 is the legal limit for a 7" rim. Worth asking around before you part with your cash. Be a shame if you had to change from your SVX rims.
I have the BFG KM2's in 255/85 and very happy with them. Noisy at 60 to 80km/h but after that the defender's sound deadening supersedes the tyre noise. It's an unconducted orchestra at 100km/h.
To the others that enquired about the 33". Mine corrected my speedo at 100km/h. With 235/85's it was 5km/h inaccurate. On my maths the increased circumference reduced my RPM at 100km/h by about 425 rpm. It has made a considerable difference to gearbox and driveline whine at highway speed. (math's wasn't my strong point, preferring the fairer sex and sport at school).
The 255/85 BFG KM2's have a marginally larger rolling diameter to the comparable sized Maaxis bighorns. The Bighorns are significantly cheaper. The 255/85's are an unusual size and are a low volume import. Expect to pay a premium over the 285/75's. Also if you do a lot of touring be prepared to wait days for replacement tyres in regional towns. They are not likely to be a stocked item.
I upgraded my ECU map soon after fitting the 33's so I can't remember if it affected my acceleration. The remapping has had a significant effect on acceleration at highway speeds. Around town my grandmother has a faster turn of speed than the defender. It would be harsh to blame the larger rubber.
As for fuel consumption. On the standard 235/85's I ran just on 10 ltr/100km combined. With the 255/85's it increased to 11.2 ltr/100km combined. I did jump from 235/85 road orientated tyres to 255/85 mud tyres. Both factors no doubt contribute to the increase in fuel consumption. Fully loaded with camping equipment i get 12 to 12.5 ltr/100kms on the black top and about 14 to 14.5 ltr/100km on the tracks.
as for the 7.0 v's 7.5" discussion. my understanding of the maths is 7.5 x 16 = 31" ie 7.5 x 2 + 16. 7.0 x 16 = 30". I understand that there was some loose sizing standards between manufacturers, but the rational of the maths was consistent.
Pyro - measures exhaust gas temperature. Over fuelling in a diesel causes an increase in combustion chamber temp indicated by an increase in exhaust gas temp. High exhaust gas temps is an indicator that you are trying to kill your engine prematurely. Easing off the right foot or changing gear if labouring in too high a gear will usually reduce the EGT.
cheers MLD