Non thirdgen but here it is,

Will 185/70R/14 tires fit on rims that currently have 195/75R/14 tires on them. They are free snow tires (4) that i am going to put on my truck. How much will that mess with the speedo, it should say i am going faster buy by how much?

Also, i just got this truck for $200 while i paint the IROC and they only problem with it is that there is an exhaust restriction, it runs fine when you first start it up and drive but after a min it starts losing power and the manifold turns red, so when i took it home the otherday i just took off the new cheap muffler that was put on it and that helped ALOT, but it is still there, so i think the cat will go next and i will put a glass pack in its place to look like a cat. Also in JCWhitney there are those turbo mufflers that look like a glass pack? how well do those work? I mean would they be good enough to replace that other muffler b/c i think that it is a restriction too seeing how much it improved the truck after it was gone. Or do you have any other suggestions like getted a used muffer from a junk yard?

 

i would sure say so. theres not much difference between the two.

 

those tires will fit, and they will not change your speedo dramatically, as far as the restriction goes, cut it all of, but do not waste to much money putting it back together, remember, the whole damn truck only cost 200

 

cut the exhaust off at the cat, so the cat, i pipe, muffler and tail pipe are gone, help out quite a bit but we still had that power problem and the manifold gettn red, so i then was like, maybe something is messed up witht the timing, mayeb when he had the engine apart he put the distrubtor in wrong, yep, advanced the timing all the way and it run soooooo much better, no pinging under HEAVY load either. so i dunno, i need some on to look up the spark plug wiring for me b/c i don't want to buy a manual for this thing. 85 nissan pickup, dual plugs and coils, 2.4l

 

btt........

 

The actual numbers according to the standards are:

Both tire sizes are designed for a 5.5 inch wide rim. However, the 185/70 has optional rims of 4.5 ,5, 6 and the 195/75 has optional rim widths of 5, 6, 6.5. The standard height of a 185/70r14 deep tread (snow type) is 24.29 and the 195/75 standard tread is 25.51 (deep tread is 25.75). The height is allowed a +/- of 3%. Your speedo may be off more than you think. Check your speedo against a buddy's car.

The load ranges are also different. A standard load 185/70 has a rating of 87 and a 195/75 a rating of 90. That means the 185/70 has a max load of 1201 lbs at 35 psi where the 195/75 has the same capacity at 29 psi (max of 1312 lbs at 35). Going above 35psi does not increase the load capacity, that is the max rated pressure on a standard load tire.

 

is it a good idea to put them on? it is just a beater, i am not gonna be loading it up or ne thing....

 

I would think you should be ok.

Where I live, there is a vehicle weight on the registration. You might look there. Here it is a shipping weight, meaning dry. Add 200-300 for fluids, plus add yourself. Otherwise, I don't think a Nissan should weigh more than my 70 Chevelle big block, which was 3800 on the scale. Using 4000 lbs, and 60% on the front axle, that's 2400 lbs which is the max for the 185/70 at 35psi. You should ok but keep the tire pressure up at 35 on the front.