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The standard equipment tires for Datsun 1200 were Bridgestone 12-inch diameter 6.00 width 4-ply (bias) tire. At least in the USA, they were whitewall tires. Optional tires were 155SR12 radial tires. Stock wheels today willl use 155SR-12 (155 mm tread width) on a 4" wide wheel. These are optimum for fuel economy as they have low friction.

Sales Window Sticker - Whitewalls N/C - Optional Radial

The largest width tire that fits a stock 1200 body are:

Front: 185 mm width
Rear: 205mm width

You will need special wheels (possibly with wheel spacers and Rolling the Guard) to fit this rubber into a 1200.

Anything from 12-inch diameter to 17-inch diameter tires can fit a 1200. The important factor is the tire height. A low-profile 17" will fit better than a regular-profile 14" tire.

A common upgrade configuration is 175/70 13" on the front, and 185/60-13 on the back.

1 Daily Care
- 1.1 Ute
2 Front Tires
3 Rear Tires
4 Low-profile Tyres
5 Easy swaps to larger tires
6 15", 16" or 17" wheels
7 Donor Cars
8 Wide Tires
9 Where to buy 12" Tires
10 Tyre Size Calculations
11 Example
12 Suppliers
13 See Also

Daily Care

USA 1972 Owners manual (see pages 26-27 for tire details):

Recommended cold inflation: 22 psi

155 SR 12 radial tires

Ute

From the 1978 B120 factory service manual (English RHD/LHD):

Front Tire size: 5.00-12-4PRULT (tubed)
Rear Tire size: 5.00-12-8PRULT (tubed)

Pressure

Front: 22 psi
Rear, Partial Load: 28 psi
Rear, Maximum Load: 47 psi

Pressure, High Speed (above 100kph/60mph)

Front: 26 psi
Rear, Partial Load: 31 psi
Rear, Maximum Load: 51 psi

NOTE: Inflation pressure should be measured when tires are cold.

Front Tires

With commonly available wheels, 175 or 185 tire will fit nicely.

A 175x60x13 tyre usually takes a 5-inch wide rim. At 540mm in diameter, they are even smaller than the stock Datsun 1000 tyre [552mm] & a lot smaller than a stock 1200 tyre [574mm].

Rear Tires

The 205x60x13 measures 576mm in diameter, virutually the same diameter as the stock Datsun 1200 12" tires, so this retains the original gearing, & they were designed around a 5 to 7" rim (5-1/2" wheel recommended). Although if you are going to run these tyres on a 13" rim it leaves a lot less room to lower the car without extensive guard work.

185x60x13 tyres measure 552mm in diameter, the same as the 1000's 5-50x12's which is smaller than the 1200's stock size [574mm] I too have found that slightly larger diameter rear tyres usually brings the odometer much closer into line with true distance traveled, & if the odometer is right, then the speedo is usually closer to the mark too.

1200 had a 155SR12 standard fitment = 155/80*12, which is almost identical to a 185/60*13 give or take 0.6mm

Low-profile Tyres

Low-profile tires have better handling qualities, turn-in, etc. But ride rougher. 60-series tires are harsher than 80-series tires, but most people will find they feel better when cornering hard.

Discussion: availability of wide tires

Easy swaps to larger tires

These keep your speedometer reading close, and fit under the stock fenders and over the stock brakes:

165/70R12
175/70R13
185/60R14

speedo and tire size discussion

15", 16" or 17" wheels

Sure, 15", 16" or 17" wheels can fit a 1200 easily. It's the width and overall tire height that is important, not the diameter of the wheel.

Discussion: my new wheels (15")

If the tires are too tall, they hit the front strut spring cups. Change struts to Stanza struts to work around this.

Donor Cars

Cars that used 12" tires:

1987-1990 Chevrolet Sprint (145SR12)
Datsun B10
Datsun B210 with/A12
Datsun B310 with/A12 (except USA)
Toyota Corolla 1200
Honda Civic
1978-1981 Ford Fiesta (155-12)
1986-1993 Ford Festiva (4 on 4.5 wheels)
1989-1994 Geo Metro (12x4, 4 on 4.5 wheels) (145SR12)
BMC Mini Cooper
1988-1995 Subaru Justy (145/80R12)

Wide Tires

Yes, stay with the wider tires, you'll be happier I think. The 155s are a bit weak for cornering (I currently have 155s).The advantage of 155/12 is that they are dirt cheap, with many wreckers practically giving them away (e.g. $10 mounted). They were still being produced massively for cars such as Suzuki Swift (Geo Metro), Honda Civic, etc, though in the late '2000s production is cut back and fewer models are available. Sometimes the discount new tire stores sell them $80/four mounted & balanced. Check the Sports section of the newspaper for the occasional tire ad.

Maximum tire width without fender flares: Rear: 205, Front: 185 For example, 205/50R15 with 15x6 wheels. Bluebird TRX (Maxima/910) wheels.

I'd go with 7" rims, simply because if you use 6" rims you're really limiting yourself to a 185/60 tyre. Anything wider and you loose a bit of crispness and steering response.
You could get 13s over your brakes with a 205/60 tyre. Or run 14*7" with a 195/60 tyre. Difference in gearing is about 5%.
reference: LB18_110 on 1200 coupe race car

Rolling the fender lip will help you get that little bit of room for wheels that are almost right. Use a baseball bat. Search the Main Forum for discussions on this technique.

Where to buy 12" Tires

But can you still get wide 12" tires? Sure:

165/70 SR12 Yokohama Y372 $42-$43 tirerack.com and SummitRacing.com
165/60 X 12 FALKEN $99.95 MiniMania.com
165/60R12 Falken FK06G $79 TalonTire.com
165/60R12 Yokohama A539 $112 TalonTire.com
165/60 12" Falken $89.95 7ent.com

TopGear (UK) carries Yokohama A539 165/60-12s.

Wrecking Yards

Best place to find 12 inch tires is a wrecking yard. They came on 1996 Geo Metro, 1994 Ford Festiva, 1990 Subaru Just, Older Honda Civics, Ford Fiesta and many other small cars. Expect to pay $10 each for like-new tires, mounted in western USA yard.

Delticom

USA http://easy-tires.com

Hercules G2000T 155/80R12
Delta National Performance 155/80 R12
Delta National Metric 155/80 R12
VeeRubber VTR 307 Trailmate 307 155/70 R12
Nankang 155/80R12
Nankang 165/70R12

TireRack

(USA) carries:

155/80-12
165/70-12

http://www.tirerack.com/tires/sizes/results.jsp?diameter=12

MiniMania

http://www.minimania.com

165/55-R12
165/60-R12
165/70-R12

165/55-R12 -- the lowest, baddest small tires on the planet

Tire size comparison

155/80-12 21.7 inch diameter 165/70-12 21.4" 155SR-13 22.8" 175/70-13 22.6"

NOTE: 165-width tires want a 4-1/2" to 6" wide wheel.

Tyre Size Calculations

Here is a tire height calculations:
Stock tire:
155/80R12 21.8"
165/70R12 21.1 (+ 3% speedometer reading)
205/40R14 20.5
185/50R13 20.3
175/50R13 19.9
165/60R12 19.8 (+ 9%)
165/50R13 19.5
205/40R13 19.5
165/55R12 19.1 (+12%)
175/70R13 22.6
195/50R15 22.7
205/45R17 23.5
205/40R18 24.4

http://www.discountpartcenter.com/tirecalc.html

So that's the disadvantage of low-profile tires: your speedometer will read too fast and the effective gearing will increase, making it rev even higher on the freeway ...What about tires for 13" or larger wheels?

Example

Lowering Tires

Stock (option) tires: 155/80R12 21.8"

sidewall: 4.9"
radius: 10.9
dia: 21.8
cir: 68.4
revs/mi:927.0

Replaced by lower-profile tires: 165/55R12 Yokohama A048R

sidewall: 3.6
radius: 9.6
dia:19.1
cir:60.1
revs/mi:1053.0

Results: Speedometer reading 12% too fast. When your speedo reads 60mph -- if it was accurate with the stock tires -- with the new tires you are actually traveling 52.8 mph.

It is also similar to going from the 3.9 diff to a 3.368 ratio. You will feel more torque, but the engine revs higher for each actual road speed.

Suppliers

Wreckers are your best bargain here ... lots of 13" tyres, even some 12s. Lots of 12s avaiable in US junk yards

Mail order

tirerack.com
Example: 205/60-R13
http://www.minimania.com

Tires

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