Bigger Tyres

Submitted: Tuesday, Mar 06, 2012 at 14:07
ThreadID: 92339 Views:3516 Replies:8 FollowUps:0
This Thread has been Archived

Related Pages

I have a 105series Standard Landcruiser 2006.
4.2litre Diesel Manual.

I am interested to hear peoples first hand experiences with the following questions.

Has anyone upsized their tyres to 285x75x16 and noticed any real life power loss/increased fuel etc.... and if so please explain/give results.....

I have no turbo on the vehicle and will not be puting one on either.
At this stage, yes it is gutless, but i am at peace with that.

I want to flick the 235x85x16 tyres i am running at the moment.
Fuel economy at this stage is a pretty consistant 14litres per 100.

Also has anyone out there fitted 315x70x16 with all my above questions again.

Back Expand Un-Read 0 Moderator

Reply By: Member - Peter S (NSW) - Tuesday, Mar 06, 2012 at 16:08

Tuesday, Mar 06, 2012 at 16:08
Hi, we have a 2003 V8 GXL fitted with BFG AT 285/75/16 had these over 5 years now, no probs at all, does use a little more fuel but have not noticed any loss of power, the speedo is out about 5klm but have fitted a scangauge and that shows correct speed also on GPS, would get these tyres again, happy with them, hope this helps, oh, normal driving use between 14 to 16 LPH. Pete
AnswerID: 479630

Reply By: Whirlwinder - Tuesday, Mar 06, 2012 at 16:40

Tuesday, Mar 06, 2012 at 16:40
We have an 80 series 1HZ and 7" rims with 267x75x16 BFG AT tyres to replace the splits that were on it.
I wish I had put 6" rims and 238 x 85x16 tyres on it. I see no advantage having the wider tyres except to feed the ego.
I put a turbo on it 6 years ago and that sure woke the old girl up. At 240k it is going better than ever! If you are sure you don't want a turbo don't ever drive one that has one fitted.
Our fuel is steady at about 13l/100 kms touring and a bit more around town.
AnswerID: 479635

Reply By: ken triton - Tuesday, Mar 06, 2012 at 17:52

Tuesday, Mar 06, 2012 at 17:52
I have a HZJ105, it is turbo / intercooled, I went from 265/70 16 to 285/75 16 BFGS. There was a noticeable decrease in torque. I spoke to the guy that Turbo ed and tuned my car on his dyno, he told me the tyre upsize cost me about 20% I would have to agree. I have since traded back to 265/75 16 and now I am happy power and torque about the same as 265/70 16's I have also noticed an improvement in the fuel economy and that is factoring in the speedo variation due to the decrease in rolling diameter.
Hope this helps.
AnswerID: 479645

Reply By: Rockape - Tuesday, Mar 06, 2012 at 20:40

Tuesday, Mar 06, 2012 at 20:40
If you bang those tyres on a naturally aspirated 1HZ that is already carting around to much weight for that engine. It will turn the vehicle into a dog and your fuel consumption will go up accordingly.

Explanation is the engine didn't put out enough torque or power when they increased the weight of the 105 series. You immediately increase fuel due to the extra rolling resistance of the 285 tyres and you change the gearing with the 285 tyres.

I can get away with my 285's due to having a chev diesel in the cruiser. I like the bigger rolling diameter because I tow in 4th gear and that gives the old girl a little more speed when I run her at the sweet spot in the rev range.

My consumption is just over 12l/h and fully loaded for a trip is now below 14l/h, fully loaded and towing 17l/h and that is before I put in new injectors.

AnswerID: 479671

Reply By: Member - Krakka - Tuesday, Mar 06, 2012 at 21:35

Tuesday, Mar 06, 2012 at 21:35
I changed from 235/85/16 to 285/75/16, definately notice a slight loss of power but mine is turbo'd. Definately feels better on and off road due to the larger contact patch. You will need a suspension lift also IMO.
AnswerID: 479684

Reply By: brownie - Wednesday, Mar 07, 2012 at 21:19

Wednesday, Mar 07, 2012 at 21:19
Mate, I've got a 2002 hzj105, It runs well on the 235/85s -they are about the same height as the original 7.50 x 16s, but a bit wider and tubeless as well.
Speedo is still accurate, I get about the same fuel consumption as you.

The hzj 105 is what it is, a good reliable & comfortable, if slowish vehicle.
Not sure what you hope to gain by fitting huge tyres, they may work ok with a turbo, but you don't have/want one of those.

Experiment a bit with the tyre pressures of your current tyres - might change the way yoiu feel about them. I run 40 front & 45 rear with a fairly heavy wagon(LR tank, tyre carrier, etc) When on sand drop them a bit, when towing put them up a bit. Works for me.

Cheers, brownie
AnswerID: 479812

Reply By: Crackles - Wednesday, Mar 07, 2012 at 21:48

Wednesday, Mar 07, 2012 at 21:48
Had a 105 diesel manual RV for 10 years with 285's on it & while yes it was slow, the funny thing is I pulled into camp at the same time as everyone else in the group ;-) On the road it moved along well even towing a trailer but it did die quickly in the hills requiring changing down earlier & revving out harder. If you don't mind dropping back to 80 or 90 kph in the hills then it's fine.
In the bush because you're using the lower gears, the bigger tyres are not really noticeable except of course the increased diameter is a real advantage in ruts, sand & rock driving.
Fuel consumption increased slightly up to 15L per 100 & a bit more when pushing hard. I was more than happy with the improved offroad ability V's the loss of road speed & consumption.
Cheers Craig..............
AnswerID: 479819

Reply By: Been-Everywhereman - Sunday, Mar 11, 2012 at 22:42

Sunday, Mar 11, 2012 at 22:42
Thanks for all the replies.
The main reason i was thinking about taller tyres is because all my life i had driven Nissan Patrols and i always used 285x75x16's and had never been stuck anywhere. Since buying the Landcruiser I am enjoying the comfort and the reliability but sometimes finding myself stuck in areas where an extra 25mm of diff height maybe could have been the difference between getting caught and maybe not.
I guess the average Joe has 31inch or 265 tyres and any extra tyre height to stay higher in tyre ruts is a positive....
AnswerID: 480122

Sponsored Links