yeah u could be right i dun now about the diametre thing ur talking bout

I'm just getting 2nd hand ones, so I'm not sure I just called up this place and its $35 each fitted and balanced with 80% thread
I'm using standard sunny struts everything stock on my car just wanted to change the wheels

195/ 50 15' fit pretty sweet as well ive got that on my ute but its got stanza struts. what is the maximum diamter of wheels u are allowed to have? as i dont wanna go out and buy thousand dollar wheels then get defected???

Will my speedo reads different as I changed the diametre of my tyres?
Stock wheels size
155/80/R13
New Rear Wheels size
185/65/R14 <---- 3.1% slower on speedo
New front Wheels size
185/60/R14 <---- 0.1% faster on speedo

According to that tyre calculator my speedo will read 3.1% slower if travelling 100 kph its actually travelling 103.1 kph.
thats for 65 series tyres, but I got 60 series tyres at the front... so i'm confused what my speedo will really read.

Razor
Sorry i didn't get back to this one, i must have gone to sleep at the wheel.

The tyre specs are laid out in the size & it basicly works as follows, using 185 x 60 x 13 as an example.

185,...This is the NOMINAL width of the tyre.
60,...This means that the sidewall is NOMINALY 60% of the tyre width
13,...This is the rim diameter that the tyre is meant to fit on.

From this it is easy to see that in a given series, the total height of the tyre increases as the width increases. If we increase the rim diameter & tyre width, but wish to retain the overall tyre diameter, then we need a lower sidewall. [bigger hole in the middle] This means that instead of the original 80 [%] profile, we need to go lower. Thats why the original 155 R 12 tyre [155 x 80 x 12] has the same overall diameter as the sample 185 x 60 x 13. The newer tyre is wider, & mounts on a bigger diameter rim, but the lower sidewall means that we keep things under control.

When juggling wheel sizes, always check the original tyre's outside diameter BEFORE rushing out & passing a big wad of cash to the tyre service salesman. As a general rule, try to keep the fronts roughly the same overall diameter as the originals & you can usually go up in overall diameter for the rear.

Increasing the wheel diameter by 1" should be regarded pretty much as a standard improvement, but 2" starts to become a problem on smaller cars, as the bigger diameters were usually used on larger cars & finding tyres narrow enough for our needs starts to become a little more difficult. Using 15" rims on a 1000 model starts to become an exercise in absolute frustration & cost.

In my view, the 60 profile tyres are probably the best value for street duty as they are reasonably available & priced. 50 series cost a bundle more, are a bit harder to find in the sizes that are good for little Datsuns, they start to sacrifice ride quality due to their reduced air volume, & do not really imorove handling much at the sorts of speeds that is sane on the street.
20" wheels with 20 series tyres [rubber bands] might look cool, but they cost squillions, ride rough, & everyone wants to steal them.
Chris
Quote:

When i get my B310 i had 155/80-13
Then i put 175/70-13 enough good.
Now i'm wearing 185/60-14 and
i'm going to put 195/50-15
This is the biggest i can get without problems

My front ones are 185/60/R14
and my rear ones are 185/65/R14

so will it change the speedo reading?

Razor
Your front tyres are listed at 578mm & this is probably about 2mm LESS than original, so they look to be pretty much ideal.
The rears are listed at 596mm which makes them about 15 or 16mm larger than original.

Soeedometer needles are propelled by a spinning magnet inside a tin drum & they are held back by a fine coiled spring. They have always been an inexact science & they usually read a little on the fast side, so in many cases the larger tyres will allow the car to catch up to the speedo.

Probably the best method is to find a stretch of road with an exact known distance. In NSW we have 5k long sections on some highways that are 1k marked & you could pull to the side of the road at the zero post [start] & set your trip meter to zero [if you have one] or take a carefull note of the exact position of your odometer. Drive in the left lane to the 5k marker & stop [not in the traffic lane dummy] Carefully study the reading & try to work out the under ot over reading as a percentage [it's not hard]
The ideal is to have it read accurately, but you could live with an error of as much as 5%. Just add or subtract the error from your speed reading to get a ball park correction.

Sometimes old Gregories manuals had some Wheels Magazine road tests in the back & these often had a chart showing the indicated speed & the true speed. My Datsun 1000 & 1200 manual has them, but the 120Y one does not. As for the Sunny? Don't know.
Chris

Quote:

If you are at stock ride height, it should "fit", but personally I think it would look pretty bad. These tires would be at leach 1.1.5" larger than stock. A 195/50-15 would be close to the stock tire diameter, and look much better, in my opinion.

as I said before I bought my wheels already...
I got 14" front and rear with 65 series at the back and 60 series at the front with 185 wide tyres
and no problemos se