"1st post from a few weeks ago"
As bizzare as this sounds here is the story.............
I used to run 33x12.5 A/T's for a year and the car had heaps of power (
well as much as you can have without a turbo),,, so i was pretty happy.... Changed oil filters with the oil every 5000kms, fuel and air filters every 10,000kms............
The other week i bought a set of Cooper S/T's in the exact same size and then the next thing i find out is that i have appeared to have lost about ½ my horsepower,,, maybe not ½ but at least quarter.....
It used to pull like a schoolboy with his first womens weekly magazine but since the tyre fitment the power has vanished... Can a more agressive tread pattern cause this???????
There is little black smoke,, all-tho i think the fuel econ has gotten worse... 15litres per 100 now,,, used to be as good as 13....
Have changed the oil and air filters recently and no change.....
Can injectors pack in as quick as this???????? or a coincidence fuel pump problem??????
Any good
places in
Adelaide to go and see without the usual $1000 entrance fee????
Regards Grant......
----------------------------------------------------------------------------------------------------------
"2nd post from a few weeks ago"
This post coincides with yesterdays post "CRAPPY GQ 4.2 diesel".....
Well it's been a good day and most tests have been completed.......
I drive a particular
hill on the way home each night after work and it is good comparison....
I think i have said before that with my 33"x12.5"x15" A/T's i used to make it up to about 90kmh by the base in 4th and by the top i used to be able to keep it around 80ish kmh which i thought was great....
So i recently buy some Cooper ST's 33x12.5x15 and all of a sudden my base speed is 80kmh and my top of the
hill speed is 60ish..... So no wonder i start to worry about things like injectors, fuel blockage etc etc etc....
Tonight i put on my original
wheels and tyres which i keep at work 31x10.5x15 A/T's and my base speed is 100kmh and i held that speed till ½ way up but didnt drop below 90kmh, even at the top...
All of my speed loggings are done by GPS and not the speedo.....
So not only what a huge difference tyre size makes but the different types of treads also as both of my 33inch types of tyres are the same OD.....
40psi used at all times...... I will leave on my 31's for a couple of tanks of fuel to see what fuel econ is.......
Thanks to all that answered my last post...
----------------------------------------------------------------------------------------------------------
"3rd post which is from now"
So i left the 31inch tyres on for a couple of weeks and travelled around getting 13litres per 100ks and got my dearly missed power back but the vehicle looked so stupid with little tyres on it with the high lift and the speedo was out by quite a bit because it was recalibrated for 33inch tyres, so when i was travelling at 90kmh the speedo was almost showing 105kmh....
I put back on the Cooper S/T's 33's x 12.5 x 15 and the power disappeared and the fuel economy went all the way to 16litres per 100k's.....
I booked the Patrol in for a 'DTS' turbo and it was fitted yesterday and today and differences are mind blowing... I should have done this a year ago.....
Before the turbo i had a measured 48kw and after the turbo a measured 77kw...
When i went to my 'test
hill' tonight it was a totally different ball game.....
In 4th gear which is what i used in my last quotes,,,,, 90kmh at the base of the
hill with the Coopers on and held 90kmh all the way to 3/4 up the
hill and then i put my foot down and it picked up to 100kmh...
I could have got to 100 by the bottom of the
hill but traffic was bad...
I have just a fuel econ run to do and then i will have to find another bee for my bonnet...