Tyres Sizes & Pressures - How to find recommended.

Tyres Sizes & Pressures - How to find recommended. was created by David Aiketgate

Posted 15 years 2 months ago #152
Tyre/wheel size/ pressure information for the MGF, MGF Trophy and the TF -

N.B.The MGRover recommended tyre types below are, in some cases, no longer available.
Below, I have included a table of common tyre types that have been used on our cars. (Some with more success than others :yesnod: As you will see in the tables.)

Firstly let me say that it is good practice to examine your tyres for unusual wear, bulges or cracking on a regular basis.
Keep an eye on pressures and tracking/alignment.

For MGF owners, - check your ride height. As lower than standard ride heights will cause your tyres to wear very quickly indeed.

Ride height
MGF ride height is measured from the centre of the front wheel vertically to the edge of the wheel arch. It should be measured on flat ground after the car has stood for a couple of hours.

MGF ride height should be 368mm+/-10mm.
MGF TROPHY ride height should be 338mm+/-10mm.

This situation can be more complicated, because it is possible to retro fit lowering pins to a standard MGF to reduce the ride height.
It is not immediately obvious whether this procedure has been carried out or not, but if you are unsure then have your tracking alignment checked.
Comparing the tracking settings with the current ride height could indicate what the ride height should be. (Assuming, of course, that the alignment was properly adjusted at the correct ride height!)

As the ride height drops it will make the tyres wear on the inner edges.

If you've absorbed all that- read on.

This information comes from the MGRover handbooks.
MGF
MGRover RECOMMENDED TYRES and PRESSURES - All models (EXCEPT THE TROPHY)




Wheels and tyres -(no other arrangements are recommended):

185/55 R15 V Goodyear NCT3 fit to 6 x 15 alloy wheels - FRONT only
205/50 R15 V Goodyear NCT3 fit to 6 x 15 alloy wheels - REAR only
215/40 R16 Z Goodyear Eagle F1 fit to 7 x 16 alloy wheels - front & rear

175/65 R14 T fit to 5.5 x 14 steel spare wheel only

Wheel alignment:

Front 10' ± 6' toe-out
Rear 10' ± 6' toe-in

Tyre pressures lbf/in bar
185/55 R15 V (front wheels only)- 26 lbf/in ......... 1.8 bar
205/50 R15 V (rear wheels only) - 28 lbf/in ......... 1.9 bar
215/40 R16 Z (front wheels) - 24 lbf/in ......... 1.7 bar
215/40 R16 Z (Rear wheels) - 28 lbf/in ......... 1.9 bar

175/65 R14 T (spare wheel only) - 30 lbf/in ........ 2.1 bar

WARNING: The spare wheel is for temporary use only, and the car must not exceed
50 mph (80 km/h) with the spare wheel fitted.
Obviously, even if you have a full sized spare wheel, because most MGF tyres are unidirectional, you may have to fit the spare with the tread rotating in the wrong direction - so, in that case, the 50mph speed limit still applies.

MGF
TROPHY
MGRover RECOMMENDED TYRES and PRESSURES

TROPHY MGF
- has a different suspension setup to the standard MGF and so you will notice that the settings and pressures are different.
(Be careful that you know which figures apply to your car.)

Wheels and tyres -(no other arrangements are recommended):

195/45 Z R16 Goodyear Eagle F1 fit to 7J x 16 alloy wheel - FRONT only
195/45 V R16 Yokohama A539 type fit to 7J x 16 alloy wheel - FRONT only
215/40 Z R16 Goodyear Eagle F1 fit to 7J x 16 alloy wheel - REAR only
215/40 V R16 Yokohama A539 type fit to 7J x 16 alloy wheel - REAR only

NOTE: Goodyear Eagle F1 tyres are directional tyres and MUST be fitted in accordance with the direction of rotation shown on the sidewall of the tyre.

Mixing Goodyear and Yokohama tyres on the same car is NOT
recommended.


Trophy Tyre Pressures - Goodyear tyres

Normal driving conditions lbf/in bar
195/45 ZR16 (front) - 24 lbf/in ......... 1.7 bar
215/40 ZR16 (rear) - 36 lbf/in ......... 2.5 bar

Trophy Tyre Pressures -Yokohama tyres

Normal driving conditions lbf/in bar

195/45 ZR16 (front) - 26 lbf/in ......... 1.8 bar
215/40 ZR16 (rear) - 36 lbf/in ......... 2.5 bar

Trophy Tyre Pressures over 100mph(160km/h) lbf/in bar

195/45 ZR16 (front) - 30 lbf/in ......... 2.1 bar
215/40 ZR16 (rear) - 36 lbf/in ......... 2.5 bar


MGTF MGRover RECOMMENDED TYRES and PRESSURES – All models

The TF has a totally different suspension setup to the MGF and the MGF Trophy. (Be careful that you know which figures apply to your car.)


MGTF Wheels and tyres -(no other arrangements are recommended):

185/55 R15 V Continental Premium Contact fit to 6 x 15 alloy wheels - FRONT only
205/50 R15 V Continental Premium Contact fit to 6 x 15 alloy wheels - REAR only
195/45 R16 Z Goodyear Eagle F1 fit to 7 x 16 alloy wheels - FRONT only
215/40 R16 Z Goodyear Eagle F1 fit to 7 x 16 alloy wheels - REAR only

175/65 R14 T fit to 5.5 x 14 - steel spare wheel only
195/45 R16 Z Goodyear Eagle F1 fit to 7 x 16 - alloy spare wheel


MGTF Tyre Pressures

Normal driving conditions lbf/in bar

195/45 ZR16 (front) - 26 lbf/in ......... 1.8 bar
215/40 ZR16 (rear) - 36 lbf/in ......... 2.5 bar

185/55 R15 V (front wheels only) - 26 lbf/in ......... 1.8 bar
205/50 R15 V (rear wheels only) - 36 lbf/in ......... 2.5 bar

175/65 R14 T (spare wheel only) - 32 lbf/in ........ 2.2 bar
195/45 R16 Z (spare wheel only) - 32 lbf/in ........ 2.2 bar

MGTF Tyre Pressures over 100mph(160km/h) lbf/in bar

195/45 ZR16 (front wheels only) -28 lbf/in ......... 1.95 bar
215/40 ZR16 (rear wheels only) -36 lbf/in ......... 2.5 bar

185/55 R15 V (front wheels only) - 28 lbf/in ......... 1.95 bar
205/50 R15 V (rear wheels only) - 36 lbf/in ......... 2.5 bar

EDIT:- It should be noted that on 15" wheels, many people have successfully substituted 195/50/15 tyres for the standard 185/55/15.
The 195 size is a more commonly used and therefore less expensive than the 185/55.

WARNING: The spare wheels are for temporary use only, and the car must not exceed 50 mph (80 km/h) with either type of spare wheel fitted.
NOTE: Goodyear Eagle F1 tyres are directional tyres and MUST be fitted in accordance with the direction of rotation shown on the sidewall of the tyre.(except for above)



MGTF Suspension settings.

MG offered 3 sports pack options as 'optional extras' for the TF:-
Sports pack 1 - 10mm lowered suspension (dampers are the same is standard but the lower spring platform in a different place) - £150
Sports Pack 2 - Uprated front disc brakes and callipers, 16" 11 spoke alloys - £850
Sports pack 3 - Uprated front disc brakes and callipers, 16" Ultra lightweight alloys - £1,850

TF160 all came with Sports pack 2 fitted as standard, but sports pack 1 was an optional extra.
All 3 sports packs were optional extras on the TF135.
None of the 3 sports packs were optional for the TF115
Some LE's and SE's also came with SP2 fitted as part of the specification though, hence there are TF115 around with SP2.

MGTF Suspension settings

standard settings


Front Wheel Alignment - Toe Out per side:

0 degrees +/- 6 minutes
0 degrees +/- 0.1 degrees
0 mm +/- 0.665 mm (15" wheels)
0 mm +/- 0.709 mm (16" wheels)

Front Wheel Camber - Negative:

0 degrees 30 minutes +/- 30 minutes
0.5 degrees +/- 0.5 degrees
3.315 mm +/- 0.315 mm

Front Wheel Castor - Positive:

4 degrees 50 minutes +/- 1 degree
4.83 degrees +/- 1 degree
29.98 mm +/- 6.71 mm

King Pin Inclination:

11 degrees 40 minutes
11.71 degrees
78.71mm

Rear Wheel Alignment - Toe In per side:

0 degrees 15 minutes =/- 6 minutes
0.25 degrees +/- 0.1 degree
1.662 mm +/- 0.67 mm (15" wheels)
1.772 mm +/- 0.71 mm (16" wheels)

Rear Wheel Camber - Negative:

1 degree +/- 30 minutes
1 degree + / - 0.5 degree
6.71 mm +/- 0.315 mm

MGTF Suspension settings

Sports Pack 1


(for use with Sports Pack 1, or X-Power springs):

Front Wheel Alignment - Toe Out per side:

0 degrees +/- 6 minutes
0 degrees +/- 0.1 degrees

Front Wheel Camber - Negative:

0 degrees +/- 05 minutes
0 degrees +/- 0.08 degrees

Front Wheel Castor - Positive:

5 degrees 28 minutes +/- 1 degree
5.47 degrees +/- 1 degree

King Pin Inclination:

11 degrees 40 minutes
11.67 degrees +/-1 degree

Rear Wheel Alignment - Toe In per side:

0 degrees 30 minutes =/- 6 minutes
0.5 degrees +/- 0.1 degree

Rear Wheel Camber - Negative:

1 degrees 33 minutes +/- 30 minutes
1.55 degrees + / - 0.5 degree


TYRE TYPE
Your cars are very sensitive to make/type of tyre.
In general they need a tyre with a stiff sidewall. You usually find stiffer sidewalls on the tyres that are higher speed rated.
Although you will not achieve speeds that require w,x,y and z speed rated tyres, The cars handling and roadholding will be improved by fitting these rated tyres. Inappropriate tyres will turn the car into a handling nightmare!

Below are two tables of several tyre makes with these ratings. They are not all encompassing, but are an attempt to give a guide to suitability.





N.B. Recently there have been some reports of sidewall cracking on Goodyear gsd2s and gsd3s and on the Marangoni Zeta Lineas. These can cause catastrophic failures.(Blowouts)

David
:shrug:

Last Edit:7 years 5 months ago by David Aiketgate
Last edit: 7 years 5 months ago by psymon.
The following user(s) said Thank You: PQD44, Leigh Ping, Sriosfor, tich65a, mirda76

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