Stock L320 tire size? (Decision made, pics!)

[KFunk740]

OK, so my truck currently has aftermarket rims with 195-60-14s, which I think are a lot smaller than stock. The speedo runs about 10mph too high (says 70 mph when I'm running 60mph). I'm pretty sure it's got the stock 4.88, so it revs pretty high on the highway. I commute an hour or so to job#2 twice a week, so highway comfort would be nice. Before I go swapping gears, I was thinking about switching to tires that are close to stock size and see how that affects its comfort on the highway. I was also thinking about reverting to stock wheels as well for a more original look.
I've got a bunch of stock wheels/tires (dry-rotted), and some are marked 7.00-14-LT, some 6.00-14, some 195/75/14, and the repair manual states 5.60-14-6PL. I've got this conversion chart here, http://www.tirerack....rsionchart.html
According to the chart, the 5.60-14 is pretty similar to the 195-60-14s that are currently on it, but I don't trust the repair manual because the speedo is so far off.
I'm thinking the 195-75-14, which is close to the 7.00-14 or 6.00-14 of my other old tires, are closer to the appropriate diameter.

So, what do you guys think would be the proper modern size for this truck? I want to bring down the highway rpms, fill up the wheel wells better, etc. Oh, and in case you're not familiar with it, there's this cool tool for comparing tire sizes: http://www.miata.net...e/tirecalc.html

[datzenmike]

520/521/620s came with 6.00x 14s. You would need to find out what size came on the 320 from the factory. Do you have the little booklet in the glove box?.

 

A 6.00 x 14 is 6" wide with a 4.8" sidewall and a total of 23.6" diameter tall. Or a 152/80R14

 

The closest to the exact size is 160/80R14 but even that is 1/3" wider and 1/2" taller than the 6.00 x 14.

 

Anything else gets wider and wider as the side wall height has to remain the same or close to 4.8" to keep the speedo accurate. A

a 75 series will go to 6.5" if you don't mind a little more width this will work

a 70 series will go to 6.85" if you don't mind a little more width this will work

a 60 series will go to 8.0" if you don't mind 2" more width this will work

[KFunk740]

You would need to find out what size came on the 320 from the factory. Do you have the little booklet in the glove box?.

 

 

No, hence the title of the thread.... I can figure out the differences between tire sizes, but I want to know what's appropriate for the L320, either based on factory recommendations or experience with the tires on an L320.

[datzenmike]

Ah. Try Mklotz70 he has/had a 320...

[DanielC]

It is getting hard to find "stock" sized tires for the mini trucks. When these trucks were made, Tires were commonly tall, and skinny, and wheel diameters were also smaller, to accommodate the relatively tall tire.

Now, the trend is to larger wheels, and tires are approaching the thickness of a rubber band, wrapped around a 20" wheel.

 

So now, you are basically looking for the tallest, skinniest 14" tire you can find. Something like a 160/80R-14, that was suggested. The "80" in the tire size is a ratio, width to diameter, so a 175/80R-14, or a 185/80R-14 would be taller than the 160/80R-14

 

You might also consider trying some 15" wheels, but for that to work, you need to find out how skinny of a tire you could get in a 15" diameter.

 

I am assuming you have a stock 1200 engine in your 320 truck. If you do, be careful about getting too tall of a tire, the taller tire will make your truck accelerate slower.

[KFunk740]

It is getting hard to find "stock" sized tires for the mini trucks. When these trucks were made, Tires were commonly tall, and skinny, and wheel diameters were also smaller, to accommodate the relatively tall tire.

Now, the trend is to larger wheels, and tires are approaching the thickness of a rubber band, wrapped around a 20" wheel.

 

So now, you are basically looking for the tallest, skinniest 14" tire you can find. Something like a 160/80R-14, that was suggested. The "80" in the tire size is a ratio, width to diameter, so a 175/80R-14, or a 185/80R-14 would be taller than the 160/80R-14

 

You might also consider trying some 15" wheels, but for that to work, you need to find out how skinny of a tire you could get in a 15" diameter.

 

I am assuming you have a stock 1200 engine in your 320 truck. If you do, be careful about getting too tall of a tire, the taller tire will make your truck accelerate slower.

 

Thanks for the help Daniel. It's actually got a 1300cc engine (J13), but that only puts me around 67hp compared to the stock 60hp. The truck will always be slow, that's not much of a concern. With the bigger tires, maybe I could actually get more use out of 1st gear. As it is, 1st gear is barely useful at all.

My BMW 2002 is for fast driving, not my truck. I'm still going thru the possibilities of similar tire sizes to the 160/80-14 on tirerack.com

[KFunk740]

What about 185/75-14?  I found a good deal on some thin whitewall radials.  25" overall diameter. 195/75-14 is also an option, but that seems a bit wide.

 

Wish I knew the total diameter of original tires.  Some of the old bias ply ones that came with my truck have a 25 to 25 1/2" diameter (the 6.00-14LT and 7.00-14LT) 

[datsunaholic]

Original diameter varied with bias ply tires.  Mike says 23.6", though every 6.00x14 bias tire I've had measured 25" or more, even worn out, and close to 26" new (actually had an unused Toyo spare once).  It had a nearly 100% aspect ratio  (6 inch tread, 6 inch sidewall).

 

185/75 R14 will be fine.  They're about the cheapest 14inch tire around, as it was a common size on crappy late 80s/early 90s American mid-size economy cars.  A little small, in my opinion, but with original narrow wheels will probably be the closest to fitting that you can readily find.

[Stoffregen Motorsports]

I installed a set of BF Goodrich whitewalls from Coker tire on my 320. They were the most accurate look I could find. And they come in a few different sizes.

 

http://www.cokertire.com/brands/bf-goodrich/695-14-bf-goodrich-5-8-whitewall-tire.html

 

 

[KFunk740]

I installed a set of BF Goodrich whitewalls from Coker tire on my 320. They were the most accurate look I could find. And they come in a few different sizes.

 

http://www.cokertire.com/brands/bf-goodrich/695-14-bf-goodrich-5-8-whitewall-tire.html

 

 

I love the look of those ones, and had been checking them out.

 

But.... two problems for me.  For one, they're way too expensive for my taste. The whitewalls I'm looking at are Hankooks for $80 each.  I can't really afford to spare much, even for those.

 

The other problem is that they're bias ply, and my truck gets driven almost daily.  I've put over 15K miles on it in less than 2 years.

I'm not sure if I trust doing bias ply.  Plus, from what I've read, they'd transmit ever bump in the road to the passengers with their extra stiff sidewalls.  My passenger (fiancee) already hates riding in the truck.  She loves the truck, but it's hard on her back, and she has to take Aleve/Ibuprofen every time we go anywhere very far.

I'm sure it doesn't help that it currently has 195/60-14s.  I'm hoping that some taller tires would make the ride more comfortable, but bias plies may negate that.

 

All else aside, I would love to have those tires, as they look perfect.  They're just like the old rotten ones I have, and they look great on the truck.  They have a weird narrow shape compared to radial tires, and I like it. 

[datsunaholic]

It's not the tires that make the ride so harsh.  It's the 1-ton payload rated springs.  The easiest method to smooth out the ride is have around 300-400lbs of stuff in the bed.  But that of course means... carrying around 300-400 lbs of stuff in the bed, lower gas mileage, longer stopping distances, etc.  But my trucks always ride nicer with a couple engine blocks in the bed.

[KFunk740]

It's not the tires that make the ride so harsh.  It's the 1-ton payload rated springs.  The easiest method to smooth out the ride is have around 300-400lbs of stuff in the bed.  But that of course means... carrying around 300-400 lbs of stuff in the bed, lower gas mileage, longer stopping distances, etc.  But my trucks always ride nicer with a couple engine blocks in the bed.

 

Yep, noticed that shortly after we bought it.  I've considered just leaving a load of worthless junk in the back.... but there goes all my cargo space for when I do need to haul stuff.

[datsunaholic]

My Mom just heaves a few 50lb bags of sand in the back of her Ranger.  Don't take much space, and can be removed if need be.

[KFunk740]

Hmmmm, perhaps the 195/75-14 may be the better option, for the 25.5" overall diameter.  Compared to the 6.00-14LTs, they still look a bit small.  205/75-14 is an option too, but not sure if its safe to put that on a 5" wide rim.

[Stoffregen Motorsports]

I had stock 320 rims in front and 620 rims in the rear. The 620 rims are wider, but I can't remember by how much.

 

The bias ply tires didn't ride harsh, but some people say they tend to wander. I liked them.

[KFunk740]

OK, got my tires off the wheels, stripped them, and primed them. 

Just  bit concerned on their widths.  Inside the rim, they're marked as '4Jx-14'

 

If you measure the total width of the rim, they're 5 1/4" wide.  But if you measure the width inside the lips (as I found as the key dimension on several figures via google), then they're 4" wide.  That seems too narrow for the 195/75-14 (5" wide min. recommended).  But I did have a worn out 195/75-14 on one of these rims.  That doesn't mean it was safe or proper, though. 

[Stoffregen Motorsports]

It's kind of an apples to oranges comparison. The wheels were made when the tires were bias ply, tall and skinny. New/modern tires tend to have a much more square shoulder profile. So in a sense, modern tires don't even translate well into the weight/size requirements. A modern truck of similar weight capacity would have a 6 inch wide rim and a 195 tire.

 

I know this is all kind of abstract, but try to decide between modern and old school. If you want old school, go with a skinny tire. If you want modern, go with a wider rim.

 

Here's an online tire size calculator to help.

http://www.rimsntires.com/specs.jsp

[datsunaholic]

Early 620s used a 4 1/2J-14 wheel.  Late ones (78-79) used a 5J-14 wheel. 

[KFunk740]

It's kind of an apples to oranges comparison. The wheels were made when the tires were bias ply, tall and skinny. New/modern tires tend to have a much more square shoulder profile. So in a sense, modern tires don't even translate well into the weight/size requirements. A modern truck of similar weight capacity would have a 6 inch wide rim and a 195 tire.

 

I know this is all kind of abstract, but try to decide between modern and old school. If you want old school, go with a skinny tire. If you want modern, go with a wider rim.

 

Here's an online tire size calculator to help.

I definitely want the old school stock rims, with tall skinny tires. I just wish they made reasonably priced radials with somewhat similar dimensions.  I'd consider the bias plies if they came in anywhere near a reasonable price as well.

 

These 4Jx-14 rims will fit a 195/75-14 tire on them, which is the closest I can get in terms of the diameter I want of 26" (25.5" diameter), and I just took an old bald one off of these rims.  I don't know if it's safe or stable for driving like that, though.  If not, then I can just go with the 185/75-14s, which are only 25" diameter, but at least they're well bigger than the 23.2" 195/60-14s that are currently on the truck with shiny wide wheels. 

 

If I could just find some white wall radial 175/85-14s, 185/80-14s, or 185/85-14s for reasonable prices, it'd be sweet.  But, I can't quuuuite get there...

[K_trip]

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[wayno]

If you drive your vehicle daily, or semi daily, use normal radial tires, if it is a show car that you don't drive much at all, then spend the money on a bias ply tires, but the vehicle will not handle good when driven, not like when it has radials.

Radial tires are a good thing, a giant step forward for the tire, but that would be my opinion.

[KFunk740]

Depending on your budget (time & money) you might fine something in the UK that you like.

The tire size you're looking for is similar to what we look for in old British sports cars & taxi's.

 

Just trying to help - best of luck!

 I managed to find one site that sold 'tyres,' and they do have plenty of the elusive 185/80-14s! Seems like all the common brands (Bridgestone, etc.) sell 185/80-14s in the UK.  Don't know why they can't ship a few here to retailers.  Something tells me though that by the time shipping to myself is calculated in, then it'll be as expensive or more than getting the good ones from Coker.

I also think these sizes are quite common in China, but can't find a retailer here that has the Chinese ones.

 

I did somehow discover a bunch of 185R14s on Tireracks website, well hidden.  I'm not sure why those don't have an aspect ratio, but the total diameter is in the 26" range, which is perfect.  No whitewall options, though. :(

[K_trip]

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[KFunk740]

^ perhaps now you understand my disclaimer better - LOL - I hope you get what you want :thumbup:

Probably gonna end up with the 185/75-14 Hankook white walls.  I'll put off ordering them for a week or two though.  Just too busy with work, and still need to paint wheels, get lug nuts that fit the steelies properly, find one more centercap, and find some beauty rings.  In the meantime I have to write a final exam, grade finals, submit final grades, and still do my day job as well. :)

So if anybody comes up with any better ideas in the next couple weeks, lemme know.

I do kind of want to get the nearly new 195/60-14s off the truck and put them on my BMW 2002, which has very bald tires.  Of course I may put my miata wheels/tires on the BMW for a few weeks in the meantime, haha.   

[KFunk740]

OK, I went with 195/75-14 Hankook H724 tires for 80 bucks each, inc. shipping from Summit Racing!  They're oddly very skinny, despite being a 195.  The tire shop guys had no idea how they could be a 195, more like a 175 or 165.  Not sure if its just these H724s that are like that, or what.  It was actually a stretch to get them onto the stock wheels.  I wanted skinny though, so a decent surprise. They seem to ride great so far.  Actually seem far more comfortable.  The tire guy was worried that the wheels might be a little bent, but that may just be sloppy manufacturing.  I haven't taken it up to highway speed yet, so we shall see. 

 

Oh, and the major work was painting the wheels to match the faded red paint.  I ended up with International Harvester red, with a couple coats of flat clearcoat to make it sufficiently shitty looking.

 

Pics!

New-old tires by KFunk740, on Flickr

 

New-old tires by KFunk740, on Flickr

new-old 4 by KFunk740, on Flickr

 

new-old 4 by KFunk740, on Flickr

new-old 3 by KFunk740, on Flickr

 

new-old 2 by KFunk740, on Flickr