Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #1

Why would a 'fender 90 be reading low? This is a 200 TDi with very low miles standard wheels and tyres and never been 'played with'. Over a 30 mile journey it reads 25 miles (consistently) when measured against other vehicles and sat nav.

 

Last edited: Nov 8, 2011

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Nov 8, 2011

• #2

different tyre size, different diff ratios, different ratio on speedo drive (in t-box) or diff T-box.

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #3

It is pretty much standard though with only 16k on the clock running 225/75 r16s. Nothing has been tinkered with and it had been serviced every 500-700 miles or so.

It just seems like a large percentage to be out?

 

Oddie

AntiSeptic Sandal Wearer

• Nov 8, 2011

• #4

Because the diameter of a 225/75 is 20% larger than the standard tyre so it thinks it has done 20% less miles than it actually has. It also thinks it is going 20% slower than it actually it, so watch our for speed cameras!

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #5

Oddie said:

Because the diameter of a 225/75 is 20% larger than the standard tyre so it thinks it has done 20% less miles than it actually has. It also thinks it is going 20% slower than it actually it, so watch our for speed cameras!

Click to expand...

:doh:

Whats the standard tyre size on an N reg 'fender then mate?

 

S

Sean

Banned

• Nov 8, 2011

• #6

750s

 

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Nov 8, 2011

• #7

Sean said:

750s

Click to expand...

7.50's

 

S

Sean

Banned

• Nov 8, 2011

• #8

The Mad Hat Man said:

7.50's

Click to expand...

thank you

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #9

Thanks, Sean.

Wishin' to appear a bit fick How big is that then..I understand 225 / 75 - what does 750 mean?

 

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Nov 8, 2011

• #10

7.5 inches

 

S

Sean

Banned

• Nov 8, 2011

• #11

Dartmoor Navigator said:

Thanks, Sean.

Wishin' to appear a bit fick How big is that then..I understand 225 / 75 - what does 750 mean?

Click to expand...

it's not 750, it's 7.50's - i missed a dot

that help ?

 

S

Sean

Banned

• Nov 8, 2011

• #12

7.50r16

 

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Nov 8, 2011

• #13

Sean said:

it's not 750, it's 7.50's - i missed a dot

that help ?

Click to expand...

Told ya

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #14

Sean said:

it's not 750, it's 7.50's - i missed a dot

that help ?

Click to expand...

Nope

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #15

Ahhh found it elsewhere... It's an imperial description code, 7.50 being standard on 109/110 LRs until sometime around 1994 or so, 6.50 on 88" and(confusingly) 205 (mm) on 90's - all being x.xx x 16 - the 16 is the rim size.

7.50's are genarally the same size, but as there is no aspect ratio they can vary quite a lot

 

S

Sean

Banned

• Nov 8, 2011

• #16

shame other peeps don't do that

 

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Nov 8, 2011

• #17

Dartmoor Navigator said:

Ahhh found it elsewhere... It's an imperial description code, 7.50 being standard on 109/110 LRs until sometime around 1994 or so, 6.50 on 88" and(confusingly) 205 (mm) on 90's - all being x.xx x 16 - the 16 is the rim size.

7.50's are genarally the same size, but as there is no aspect ratio they can vary quite a lot

Click to expand...

so - what didnt yu understand about 7.50 INCHES???? :doh:

 

Dartmoor Navigator

Well-Known Member

• Nov 8, 2011

• #18

The Mad Hat Man said:

so - what didnt yu understand about 7.50 INCHES???? :doh:

Click to expand...

I int foldin' it in 'alf for nobody

 

Oldseadog

Well-Known Member

• Nov 9, 2011

• #19

Dartmoor Navigator said:

I int foldin' it in 'alf for nobody

Click to expand...

Half??? Yeah right!!!

Mine don't take a three-fold

OSD