cgovia Posted October 4, 2008 Report Share Posted October 4, 2008 what would be the best tire to run on my 75 620 with 18inch titain rims 225-40-18 or 255-45-18? got 3inch blocks Quote Link to comment
Cuts metal like mad Posted October 4, 2008 Report Share Posted October 4, 2008 I had 225-40s, the rims touched the tc/radius rods. with 255-45s the tires will touch and reduce your turning circle even more. Quote Link to comment
datzenmike Posted October 4, 2008 Report Share Posted October 4, 2008 The 40 would be about 25" tall the 45s would be almost an inch taller What were the size of the stock tires for your truck? Quote Link to comment
]2eDeYe Posted October 4, 2008 Report Share Posted October 4, 2008 Mike is dead on, my 40's measure 25". It also depends on the manufacturer as some of the same sizes measure a bit different in reality. Quote Link to comment
datzenmike Posted October 4, 2008 Report Share Posted October 4, 2008 225/40/18= 25.09" tall 8.86" wide 225/45/18= 25.97" tall What is the stock 620 tire size? My '78 manual ... I can't find it if it's there. Quote Link to comment
]2eDeYe Posted October 4, 2008 Report Share Posted October 4, 2008 Tall and scrawny size :D Quote Link to comment
polini Posted October 4, 2008 Report Share Posted October 4, 2008 wassup bradda sorry off the subject but theres a JCCS cruise on Oct 12 at wapio regional park hopfully you can make it out. pm me maybe we can roll in together. (the guy at 7-11 in kaneohe with the brown 720) let me know Quote Link to comment
cgovia Posted October 4, 2008 Author Report Share Posted October 4, 2008 hows the ride on the 40s Quote Link to comment
SickDrift Posted October 4, 2008 Report Share Posted October 4, 2008 What is the stock 620 tire size? My '78 manual ... I can't find it if it's there. The 78 service manual I just looked at said the factory size is 6.00/14, the same as the earlier models, 175/70r14. Maybe a 205/40r18? Would be closer to the factory size in that case. Guess it depends on the width of your 18's. Quote Link to comment
]2eDeYe Posted October 4, 2008 Report Share Posted October 4, 2008 hows the ride on the 40s Tight, a little rough. Cornered oh so nice. :cool: Quote Link to comment
datzenmike Posted October 4, 2008 Report Share Posted October 4, 2008 175/70/14s are 6.89" wide and 23.6" tall or 1.44" smaller than the 225/40/18s Quote Link to comment
]2eDeYe Posted October 4, 2008 Report Share Posted October 4, 2008 That's not to far off, wonder how much that affects the speedo... Quote Link to comment
datzenmike Posted October 4, 2008 Report Share Posted October 4, 2008 If you switch from the stock 175/70/14 to the larger 225/40/18 when you are actually going: 30mph your speedo reads 28.28mph 60mph your speedo reads 56.55mph 100mph your speedo reads 94.26 Quote Link to comment
Bleach Posted October 4, 2008 Report Share Posted October 4, 2008 Once again its a question of the correct factory tire size. I think 175/70-14 is smaller than stock for 1975. I just ran a search on 6.00-14 and one website says 680mm diameter. I can't find a tire that matches that. 185/85/14 is 670mm diameter. I have always thought that 195/80/14 was stock tire size. (667mm) If that is the case then 225/45/18 will keep your speedo correct. Quote Link to comment
datzenmike Posted October 4, 2008 Report Share Posted October 4, 2008 I couldn't find a conversion from the old 6.00 X 14 to the metric. My '64 Dodge had 7.75/14s on it.My 70 Dart had E7014s ????? Quote Link to comment
Bleach Posted October 4, 2008 Report Share Posted October 4, 2008 I just typed "6.00-14" into Google. It was one of the first websites. Says 680mm diameter. No normal tire size measurements though. I then used a tire size calculator to look at the diameter of a few tire sizes on 14's. Quote Link to comment
SickDrift Posted October 4, 2008 Report Share Posted October 4, 2008 I really dont think that the chinese tires being produced today are comparable to the original tires that came on our vehices. Here is a link to tireracks conversion chart; I will also add that even when I was working at Americas/Discount Tire Co, we would occasionally refer to their docs as they were generally considered to be trustworthy: http://www.tirerack.com/tires/tiretech/45_conversionchart.html I remember a post on the site here where someone had an original spare still mounted under their truck. We can settle this issue, once and for all, if this member would kindly measure their tire, fully inflated, as this subject has come up several times even in the short time Ive been here. Quote Link to comment
Bleach Posted October 4, 2008 Report Share Posted October 4, 2008 Is a spare generally the same size as the tires on hubs? 185/65/14 is tiny. Datsun advertised the 620 as comming with large truck tires. Quote Link to comment
SickDrift Posted October 5, 2008 Report Share Posted October 5, 2008 Is a spare generally the same size as the tires on hubs? 185/65/14 is tiny. Datsun advertised the 620 as comming with large truck tires. Spares *should* have been identical size to the rest of the tires on the truck. As far as the tires being advertised as large... who knows? That Quote Link to comment
datzenmike Posted October 5, 2008 Report Share Posted October 5, 2008 Would be on a truck. Cars wouldn't matter as much often using space savers. Can you imagine taking a full load of pig shit to town and the tire pops and you have to use a space saver tire to get there?:D My '71 521 had the original tire on it in the early '80s. The release mechanism was rusted solid and I broke it to get it off. It was a rugged nylon ply tire that did not match my P225/75R14 M&S tires. Quote Link to comment
Cuts metal like mad Posted October 5, 2008 Report Share Posted October 5, 2008 680mm/25.4mm=26.77inches Quote Link to comment
lynchfourtwenty Posted October 5, 2008 Report Share Posted October 5, 2008 (edited) i have a question.. im puttin that 83 maxima 5spd in my truck, and im not changin the cog.. the tires i run are 245/50/r16, and usin the tire calculator an comparing them to 175/70/r14 my speedo at 60mph i would be doin 65mph, thats all with my stock 4spd ofcourse, now the question is... what speed would i my speedo read when i put the new tranny in... im guessing its going to be even further off like prolly 7-10mph in the same direction.. it would be cool if it "corrected" it tho.. but thats doubt full.. i'd have to run even smaller tires i think edit: the tires i want are 195/40/16 an comparing to 175/70/14 the speedo would read 60 an i would only be doin 56 Edited October 5, 2008 by lynchfourtwenty Quote Link to comment
SickDrift Posted October 5, 2008 Report Share Posted October 5, 2008 i have a question.. im puttin that 83 maxima 5spd in my truck, and im not changin the cog.. the tires i run are 245/50/r16, and usin the tire calculator an comparing them to 175/70/r14 my speedo at 60mph i would be doin 65mph, thats all with my stock 4spd ofcourse, now the question is... what speed would i my speedo read when i put the new tranny in... im guessing its going to be even further off like prolly 7-10mph in the same direction.. it would be cool if it "corrected" it tho.. but thats doubt full.. i'd have to run even smaller tires i think edit: the tires i want are 195/40/16 an comparing to 175/70/14 the speedo would read 60 an i would only be doin 56 I dont know the answer to your question. To be honest, the more I thought about it, the more confused I got. However, this may not be of any help, but I think it's helpful nonetheless: http://www.geocities.com/z_design_studio/ Quote Link to comment
datzenmike Posted October 5, 2008 Report Share Posted October 5, 2008 i have a question.. im puttin that 83 maxima 5spd in my truck, and im not changin the cog.. the tires i run are 245/50/r16, and usin the tire calculator an comparing them to 175/70/r14 my speedo at 60mph i would be doin 65mph, thats all with my stock 4spd ofcourse, now the question is... what speed would i my speedo read when i put the new tranny in... im guessing its going to be even further off like prolly 7-10mph in the same direction.. it would be cool if it "corrected" it tho.. but thats doubt full.. i'd have to run even smaller tires i think edit: the tires i want are 195/40/16 an comparing to 175/70/14 the speedo would read 60 an i would only be doin 56 The 5spd cog would depend on what size tires were on the Maxima and the rear end ratio. Just pop your 4spd cog into the 5 spd and at least the speedo will stay the same as it is now. Only takes a few minutes. Quote Link to comment
lynchfourtwenty Posted October 5, 2008 Report Share Posted October 5, 2008 problem with that is i sold my old tranny its not a big deal.. i will make gf drive next to me an i will do the math Quote Link to comment
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