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.