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Really general stuff

PostPosted: Sat May 12, 2007 11:39 pm
by First Subaru
Hi guys, just wanna share a bit of what i observed. Bought a gps the other day, i realised that when my speedo was showing 100km/h my gps only 90? thats about 10% different. Anyone had similiar experience?

btw....went to look at a VW R32 today.....the engine sounds like.....music... :lol:

PostPosted: Sun May 13, 2007 12:13 am
by WeeGraeme
Do you have factory standard size tyres?

On my car (which isn't yet a Liberty) my speedo reads the same as my PDA satnav, yet when I go through the etoll, the speed detector frowns at me. We have satellite tracking in the vehicles at work. I've compared my satnav to the reading from the satellite tracking, and they're the same.

PostPosted: Sun May 13, 2007 12:30 am
by MY07GT
Yeah thats usual. Libs have a lower reading than actual. There was a thread sumwhere in here.

The golf is not worth the money i dont reckon. I raced one and left it.

Phil.

PostPosted: Sun May 13, 2007 8:27 am
by EJ25
i say wait for the wrx sti, i honestly love it atm..

Re: Really general stuff

PostPosted: Sun May 13, 2007 9:23 am
by Ric
First Subaru wrote: i realised that when my speedo was showing 100km/h my gps only 90? thats about 10% different.

That's a bit excessive, 95-97 would be more normal.
As weegraeme asked, are you running stock wheels and tyres?

PostPosted: Sun May 13, 2007 9:41 am
by First Subaru
everything is stock and factory fitted on my car MY07 GTB......that makes me wonder.... :?

PostPosted: Tue May 15, 2007 2:56 pm
by WeeGraeme
I guess it's more difficult to tell, but is the odometer out by the same percentage?

PostPosted: Tue May 15, 2007 7:12 pm
by First Subaru
From my observation, yea roughly 10%

PostPosted: Tue May 15, 2007 9:21 pm
by gt_dicko
according to the dodgy things on the freeway, and the ones you get around the residential streets I'm about 7-8% out.

This also proved true when a member of the constabulary pulled me up for going slightly too fast down a nice wide open country highway.... :? expensive lesson that one....

PostPosted: Thu May 17, 2007 1:59 pm
by hosko11
I've got an MY07 GTB (stock) as well with less than 1000ks on the clock and did the GPS/Speedo test after noticing everyone passing me at 102 kph on the speedo. At 100kph on the GPS the speedo indicated 108kph. A tolerance of 8% in my book is a bit excessive. I didn't bother to check the accuracy at 60kph, so I don't know if it's a linear 8% or not.

Does anyone know if Subaru can correct this? Additionally, does this mean the odometer is registering 8% more ks than it should??? 40,000ks travelled = 43,200ks on the odometer......

PostPosted: Wed Aug 15, 2007 8:26 pm
by sogg
Sorry to dig up a old thread.
But i am noticing the same thing with my MY08 Gt specB everything stock. Speedo is on 100kph. the subaru sat nav says 94kph, and the speed test thing on the freeway says 94kph. Just wondering if anyone has brought this issue up with subaru yet?

PostPosted: Wed Aug 15, 2007 8:45 pm
by buggermedumplings
Same problem here with MY07 GTB, 4500kms, driving back on Geelong road, sitting on 100 and speed detector showed 92. Even timed it with the road markers and got the same result.

PostPosted: Thu Aug 16, 2007 10:30 am
by viriix
I timed my odometre calibration when i was coming back from Canberra since i was bored at night.

Counted it for 4-5km and it seemed pretty spot on.

I know in general that the speed your doing is usually slower than what is shown on the dash, so it sounds about right that it shows your doing 100km on the dash and 94 on the sat.

Mines pretty similar, i remember I was sitting on 90km/h and my navman was telling me i was doing 82-83k

My Honda Euro previously was similar as well. I remember I could sit at 120km/h on the dash but the gps would tell me i was doing 112km etc.

PostPosted: Thu Aug 16, 2007 10:42 am
by MIB
Not really worth bringing up with Subaru as every manufacturer does it. Mine's about 93 when indicating 100. I set the cruise from the sat nav, not the speedo. There are so many variables to a 'geared' speed calulator it would be near impossible to get right at ALL speeds, tyre wear, tyre pressures (remembering that the tyres 'grow' as they get heat in them - have a look at drag car tyres growing, although not to anywhere near that extent, road tyres do the same). My Lib is pretty much spot on at 60kmh which is obviously where they geared it. Once all cars run sat nav as standard you'll start to see the speedo being driven from that... but then what happens when you go into a tunnel?

For the record, the most accurate speedo I've seen is on my new motorbike, spot on at (well maybe half a kay out) at 110kmh... BMW. My old go fast bikes were worse than cars... 10-15% out, Honda being the worst (or most optimistic)