Need help quick- will this tire be OK?

It obviously is not 100% identical but they are very similar tires with near identical tread patterns so you will be fine.

MB860 ?

 

I am curious as to whether all the tires should be the same pressure or does the newer one require more to equal the sidewall and deformation characteristics of the old ones. Your new one is likely rated at 51psi max instead of 44psi like the OEM version.

 

I hadn't noticed the OEM Fuel Maxs were 44 psi on the sidewall. I'm still going to run mine at 48/46 until I decide to try another pressure.

About 60% of the way down the page, this says there is usually a difference in construction between an S and an H tire
http://www.barrystiretech.com/speedratings.html

 

I'm pretty sure that's the case anyway. I get mixed up sometimes.

 

I know that for safety and load carrying purposes, the tire size and load rating index are more important than the max psi listed on the tire. Generally, "P" tires should not be run higher than 35 psi.

 

I don't think it will make any difference. Even if the new tire is slightly different in some ways the car has a good VSC system that will compensate in the unlikely event you need to take drastic evasive action and it starts to break loose.

If you have any doubts contact the tire manufacturer, they usually have a phone number and email address on their web site.

If you are uncomfortable about it put two new tires on, just be sure they are on the same end of the car, i.e. both on the front or both on the back.

 

True but pressure changes load carrying capacity and characteristics as does top speed. I.E. when carrying heavy loads or traveling at very high speeds you will need to increase pressure accordingly. As such there is not one perfect pressure setting for all circumstances. So will the 51psi tire work exactly the same as the 44psi tire if they are both ran at 35psi? What about at 44psi?

Additionally the OEM version is S rated and the retail version is H rated. Load ratings are the same, however.

 

My understanding is that the load tables will tell you how much pressure is necessary to achieve a desired load carrying amount, based on the size and load index. OEMs will obviously request a slightly higher psi as a margin of error, too. Sometimes, further tuning is done for handling effects.

CapriRacer over on bobistheoilguy is a tire engineer and has explained this in a number of posts on that site and could probably explain better, but that's the understanding I've gathered from his posts.

Here is a link to some load tables, but they do not have all sizes:

http://www.toyotires.ca/sites/default/files/loadinflationtable.pdf