Ground Speed difference

[Foxy48 Member Find all posts View Profile Close Foxy48]

Hi People, People who have change their OE tires recently from stock to another size what ground speed difference have you noticed? I currently am running stock 265 65 17 and I'm thinking about going to 265 70 17 which is a slightly taller tire so I would like to know what the Taco difference is so I can adjust my driving to avoid the"flash for cash" and such .Can you help Cheers Foxy

[Dakrol Junior Member Find all posts View Profile Close Dakrol]

Usefull calculator below

http://www.performanceprobe.com/inde...calc&page=tire

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

If you compared your speedo to a GPS you would find your speedo is reading fast. If you change to 70 sereis tyres you will find your speedo will now read correct.

Cheers Andrew

[Foxy48 Member Find all posts View Profile Close Foxy48]

Thank you for the replies, My son God bless him is a boy in blue and he says not to rely on the GPS as that is not always exact. Over here in SA they are starting to hit"creepers " so I pretty well need to know just where the speed is .I'll have a go with the formula Thank you Foxy

[Foxy48 Member Find all posts View Profile Close Foxy48]

Just did the calculator but it is in MPH not K's .I'm not that computer literate to no how to change it but not to worry it seems, going a little taller won't make that much difference Cheers Foxy

[Dakrol Junior Member Find all posts View Profile Close Dakrol]

In that case try this one

http://www.csgnetwork.com/speedocalibcalc.html

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Hi AJ, depends on what year model as to the speed been out. Myn is an 05 and is spot on the dot running factory tyres (Dunlop grandtrecks) If I went to 70 firstly it would put my speedo out by approx 4 klm eg speedo reading 60klm but actual speed would be 64. Also here in NSW makes me illegal as the rolling diameter is over the allowed specs (for memory 15mm bigger). Not to mention insurance issues as NRMA has informed me, problem is trying to get a good quality muddy or AT in a stronger side wall at the factory 65 profile.......Probably most people on PP who have upgraded tyres would be running 70 profile........Cheers Steve

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

You are correct about the year of manufacture Steve, the law changed around 2007 and since then all new vehicles have speedos that read fast. This is in the 150 section so it has to be post 2007

Foxy, if you don't want to compare to the GPS then thats fine, just be aware that your speedo does not read correctly so if you drive by that you are not travelling at the speed you think you are.

Cheers Andrew

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Sorry AJ, just realized that myself its in the 150 section. I just think every one has a 120 lol.....Cheers Steve

[Bear63 Senior Member Find all posts View Profile Close Bear63]

My 150 is out by about 6 k's @ 110 kph according to my gps , pretty much the same as what other people have told me

[Foxy48 Member Find all posts View Profile Close Foxy48]

hi people thank you for replying, DAKROL, I used the other calculator and it kept saying NaN I'm not too sure what that means .AJ120,Mate I will still compare with a GPS just to get some idea of where the real speed is .Yep I do have the 150 SX shorty and very happy with it .Just me and the Lady now the children are gone so it's just the 2 of us and the grandchildren occasionally and with seats in the back no worries at all ..
It seems to be saying that if I go to the 265 70 17 the real speed will be what the taco says or am I wrong Cheers Foxy

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

It seems to be saying that if I go to the 265 70 17 the real speed will be what the taco says or am I wrong Cheers Foxy

Yes that is correct, as I said in my first post

If you compared your speedo to a GPS you would find your speedo is reading fast. If you change to 70 sereis tyres you will find your speedo will now read correct.

Cheers Andrew

Cheers Andrew

[yowie Advanced Member Find all posts View Profile Close yowie]

Thank you for the replies, My son God bless him is a boy in blue and he says not to rely on the GPS as that is not always exact. Over here in SA they are starting to hit"creepers " so I pretty well need to know just where the speed is .I'll have a go with the formula Thank you Foxy

So at what speed above the limit are the cops handing out the tickets?

[brogers Advanced Member Find all posts View Profile Close brogers]

So at what speed above the limit are the cops handing out the tickets?

I have some friends in the police, and they said to me that they have been told by superiors "the speed limit is the speed limit", and it looks like they are going to enforce zero tolerance to speeding...ie anything above the limit may be enforced...thats what I'm told anyway.

[craigm Addicted PP Member Find all posts View Profile Close craigm]

I understand that Qld Speed Cameras are set for +10%. Unlike NSW where its a LOT less....