33Inch Tyres.

[ptcb]

Gday guys. Am looking to put 33's on my 3.0l GU wagon. Will this have much of an impact on power and economy? The car is standard, no chips or exhaust. Will I have to power up to run these or change diff ratio's or will she still go alright.....

[MEGOMONSTER]

It will be good as gold.
You shouldn't notice too much power loss anyway, but your speedo will be out
3-5kms.
Plus it will give you a reason to chip and exhaust it.

[ptcb]

I like your reply MEGO, L
lift first!!

[threedogs]

Gee Mego I certainly feel the difference when I put my 305s on
Not as much going but you feel it stopping. Its a big rolling mass
33x12.5x 16", Thats why I run 2 sets, Fuel wise makes a big difference as well IMO
mainly in mud Pattern as that generally what 33s are, muddies. Summing up it takes a bit out of
accelleration, big strain on brakes, use more fuel and speedo out a touch, would I take them off
Hell no, M2cW

Edit ,,,,then again I have chip and full 3" zorst

[P4trol]

So 33s on a 3L doesn't correct the speedo to spot on like in a 2.8?

[MEGOMONSTER]

So 33s on a 3L doesn't correct the speedo to spot on like in a 2.8?

My mate put 285/70/17 (33-11.50-17 I think) Cooper STT and we stopped on the Hume hwy, zeros the clock and continued for 100ks at 100kph.
He was definitely going faster than I was with a standard patrol.
And was also 3 or 4 k's short on the clock over the same distance.

[P4trol]

Those results were to be expected. Speedos are allowed to read under. Most cars I have tested (informally) are spot on at 40km/h

The standard tyre size is ?what? on a patrol?

People usually upgrade to 285/75/r16 when they go 33s?

The best way to test is via GPS. Results will vary slightly with tyre wear.


So... You can download GPS speedo apps for your phone. Who is going to do a test?

[vfamily]

when I fitted 285 75 16 km2s It made my speedo spot on

[Clunk]

But do they sap the power from the 3ltr donks as ask in the original post?...... Mines a 4.2 petrol, so have not noticed a great deal of difference

MCcrappatappalot signing on..............

[Alitis007]

The last couple of days i've been running 33's on my 4.5, i have noticed its a little slower on take off, my speedo is spot on and my cruising RPM has dropped by 100rpm also looks like i'm getting a bit better economy coz of the lower rpm. You still have the power but your acceleration suffers a little but i think it all depends on your diff ratios, but its very minimal. Also noticed its a little harder to pull up in a hurry too.

[ptcb]

Any 3.0l guys out there with 33's on with an opinion? Love ro hear it!

[Clunk]

Any 3.0l guys out there with 33's on with an opinion? Love ro hear it!

I would probably say that you'd lose a bit in acceleration as Altis already stated but how much I couldn't say........ would have to wait for the 3lt brigade to pipe up

MCCrappatappalot signing in!!!

[Alitis007]

Any 3.0l guys out there with 33's on with an opinion? Love ro hear it!

Threedogs and Megomonster have 3ltr mate, so a couple already have

[vfamily]

I noticed the effect on braking and accerleration but not enough to be a concern mine is auto

[Rumcajs]

You also need to consider a legality of such tyres on your vehicle depending in which state you are residing. While you may not be pulled over, certainly in a case of an accident with casualties you may increase your liability beyond what you can afford especially when the lawyers and insurance get involved. Especially because stopping distance can get affected never mind fuel usage. If in SA you'll need to have the 33" tyres engineered as max increase in diameter allowed is 15 mm from largest tyre listed on the tyre placard. While I don't necessary agree, the liabilities can be horrendous once personal injury lawyers get involved.
Cheers

[ptcb]

Thanks Fella's, plenty to consider. Might need a new Zort!

[Morton]

PCTB,
I have run 33's for 5 years now, you lose in accelation certainly, it is harder slightly to pull away at lights, causes slight turbo lag when not use to it, you do need to change gearing slightly when going through the gears, a very slight tweek of the turbo (1/8 -1/4) turn will pick all of this up, dont touch it if you dont know what your doing, better economy on highway is slightly noticable, worse economy in city is slightly noticable.

RUMJAS
the 15mm you are talking about is that in total height?, going from 32" standard to next size 33" should be a height gain of only 15mm, the height is based on the centre of the rim to the top of the tyre, this is legal even in Queensland who have the weirdest height rules

[Bloodyaussie]

Mudski runs both 32's and 33's...ask him?

[BearGUST]

I've got 33's on my ZD30 Manual wagon, you will notice that she needs to work a bit harder to get going (and stopping).
I've got chip, exhaust, etc to try counteract it.

[ben 4.2td]

I put 285/75 16 on my Patrol 4.2 td 12/2006, spedo changed by 8km/hr and could not change into fifth gear till nearly 110km/hr without to much strain on the engine. Has after market turbo and exhaust. Makes it a bit less fun to drive as you feel you have to push it along all the time. Loves being over 110km/hr when it gets there but to many speed cameras. Will be down sizing next tyre change.

[MudRunnerTD]

I put 285/75 16 on my Patrol 4.2 td 12/2006, spedo changed by 8km/hr and could not change into fifth gear till nearly 110km/hr without to much strain on the engine. Has after market turbo and exhaust. Makes it a bit less fun to drive as you feel you have to push it along all the time. Loves being over 110km/hr when it gets there but to many speed cameras. Will be down sizing next tyre change.

Wow! You need a Dyno Tune mate or your Turbo is ridiculously too big? I have no trouble grabbing 5th running 315s, my 285s and it is cruising at 2300 revs at 100kph.

[ben 4.2td]

That turbo is the original turbo but upgraded with 3 inch tuned exhaust. Goes hard in all 4 gears but just has no talk in 5th, can change into fifth at lower revs but strained motor and vibrates slightly if you try and accelerate, taken to two turbo diesel mechanic said it seems to be tuned and turbo fine, just said wheels too big and deal with it.