different tire sizes

[bignycdon]

just got truck 2 months ago ....i am looking to buy new tires....i looked at my tires and i see that my front tires are 305/40/22 and my rear tires are 305/45/22....i know that the truck comes with 305/40/22 but i wonder if the person put these tires on for better performance or the dealer just put some tires on he had laying around...i am thinking of replacing all 4 tires with 305/45/22 because i read that they give the truck a smoother ride....

 

[SANCHOBA]

i can think of two reasons not to go with 45's

1. taller side wall=doesn't handle as well (more flex when cornering)
2. overall diameter or height (would be slightly taller and in effect it would be like changing your gearing), your acceleration would suffer.

P.S. you can go WIDER though, i plan on putting 325/40/22s' on the rear

 

[oldguysrt10]

Both changes result in similar results. Going from a 305/40-22 to a 305/45-22results in a 1.2" (3.8%) increase in tire diameter. You may get a slightly smoother (probably not noticeable) ride. You will get slightly poorer acceleration (probably won't notice on seat of pants dyno but will notice at the track) both from the effective gear ratio change and the probable increase in rotating mass. Bottom line is you're increasing sidewall height by 5% versus stock (40 aspect ratio to 45 aspect ratio).

Going from 305/40-22 to a 325/40-22 results in a .6" (1.9%) increase in tire diameter. The change here is from applying the aspect ratio to a wider tire. This change won't result in a smoother ride in that you have more surface contact even though slightly more sidewall. You may see slightly poorer acceleration from effective gear ratio change and potential rotating mass increase depending. Rotating mass might be lower though depending on brand of tire selected due to differing weights.

oldguy

 

[bignycdon]

thanks ....so then somebody just put the wrong size on the rear

 

[SANCHOBA]

that would be my guess.

 

[davo19]

Both changes result in similar results. Going from a 305/40-22 to a 305/45-22results in a 1.2" (3.8%) increase in tire diameter. You may get a slightly smoother (probably not noticeable) ride. You will get slightly poorer acceleration (probably won't notice on seat of pants dyno but will notice at the track) both from the effective gear ratio change and the probable increase in rotating mass. Bottom line is you're increasing sidewall height by 5% versus stock (40 aspect ratio to 45 aspect ratio).

Going from 305/40-22 to a 325/40-22 results in a .6" (1.9%) increase in tire diameter. The change here is from applying the aspect ratio to a wider tire. This change won't result in a smoother ride in that you have more surface contact even though slightly more sidewall. You may see slightly poorer acceleration from effective gear ratio change and potential rotating mass increase depending. Rotating mass might be lower though depending on brand of tire selected due to differing weights.

oldguy

i beg to differ...i put the 45's on because the 40's were just too hard, especially after the x-metal drop...now the ride is definately smoother and very noticeable...the flex in the sidewall was what my truck needed, as for handling...no noticeable change, the drop/tire size complemented each other for the ride and handling quality that i was`looking for. i would not go back to 40's even if they were free!!!but thats just my thoughts...

 

[guinnessboy]

im up in the air myself, i need new tires and i dont race it too much, im thinking the 45's might be the way to go, im looking at the yokohamas right now

 

[davo19]

i dont do alot of track days, if i do run, its usually once or twice...i went with the general grabber uhp...got them for a very good price...

 

[walenator]

Just get away from the stock tire and you'll really like the difference. I have Generals UHP's but it appears all other tires provide improvements over the stock tires for daily street driving.

 

[bignycdon]

i have Yokohama spec-x 305/45/22 on the rear....those tires look new ....i got the factory tires on front pirelli305/40/22 and those are shot....i thank everyone for the input but i am going to go with the 305/45/22 for 3 reasons...(1) i use my truck everyday (2) we don't have a track in NYC so i will never race my truck (3) it is cheaper for me to buy 2 tires then 4....thanks again

 

[HOT RAM]

Good reasons.When you do need to buy all 4,try the General grabber UHPs.They are much better ride and handling than stock Pirellis.I went with stock size and noticed a tremendous difference in ride quality.No need to go bigger when using these tires.

 

[oldguysrt10]

i beg to differ...i put the 45's on because the 40's were just too hard, especially after the x-metal drop...now the ride is definately smoother and very noticeable...the flex in the sidewall was what my truck needed, as for handling...no noticeable change, the drop/tire size complemented each other for the ride and handling quality that i was`looking for. i would not go back to 40's even if they were free!!!but thats just my thoughts...

There are more variables than just tire size. My comments were with the assumption of same brand, same load rating, same speed rating, and same inflation. The same size tire but with just 1 lower speed rating will be smoother due to a softer sidewall. Add 5% to the aspect ratio on a softer sidewall and it's even smoother. It really just winds up being personal preference depending on what's individually important. I've had both good and bad experiences on new tires when I went with other than OEM. I stayed with the Pirellis when I bought my second set because I couldn't afford my first choice. I expect to do different next time.

oldguy

 

[HOT RAM]

There are more variables than just tire size. My comments were with the assumption of same brand, same load rating, same speed rating, and same inflation. The same size tire but with just 1 lower speed rating will be smoother due to a softer sidewall. Add 5% to the aspect ratio on a softer sidewall and it's even smoother. It really just winds up being personal preference depending on what's individually important. I've had both good and bad experiences on new tires when I went with other than OEM. I stayed with the Pirellis when I bought my second set because I couldn't afford my first choice. I expect to do different next time.

oldguy

Maybe this is why the Generals feel better,due to the lower speed rating ?

Very few of us need the higher rating anyway,that is for sustained (more than just a quick run up to max speed) extreme speed isn't it ?

 

[davo19]

There are more variables than just tire size. My comments were with the assumption of same brand, same load rating, same speed rating, and same inflation. The same size tire but with just 1 lower speed rating will be smoother due to a softer sidewall. Add 5% to the aspect ratio on a softer sidewall and it's even smoother. It really just winds up being personal preference depending on what's individually important. I've had both good and bad experiences on new tires when I went with other than OEM. I stayed with the Pirellis when I bought my second set because I couldn't afford my first choice. I expect to do different next time.

oldguy

the generals werent my first choice either, but i got the set for $132.00 each. then i mounted and balanced myself. so far i am very pleased. the pirelli was about $180.00+... i really wanted the bfg's $$$$$...lol

 

[oldguysrt10]

the generals werent my first choice either, but i got the set for $132.00 each. then i mounted and balanced myself. so far i am very pleased. the pirelli was about $180.00+... i really wanted the bfg's $$$$$...lol

Yep, B.F. Goodrich was my first choice too. In hindsight I wish I'd spent the extra bucks.

oldguy

 

[davo19]

i used to work for michelin, the wife still does, her discount wasnt enough to justify the bucks...but next time it will be a different situation...i had to get something quick cause i had cut two tires that saturday night . i got a guy at firestone to order the generals from a local warehouse for me...