Quote:
Originally Posted by nZtiZia
gqgambler
22" tire load rating is less than 20/21" tires:
22" are rated for 104 front and 107 rear
21" are rated for 107 front and 110 rear
20" are rated for 110 front and 112 rear (staggered), 110 front/rear (square)
demet123 i wouldn't recommend going 22" at all on the 45e. BMW removes this option from the build for a reason. another way to look at it for staying with 20" RFTs is that it gives peace of mind if your partner gets a flat while driving, more than likely they can continue to drive to safety versus pulling over. i mean, they can do this with 21" RFTs as well but you'll be the one dealing with its staggered disadvantages come repair/replacement time.
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Thanks for posting those numbers.
I know many people are onboard with the 20s, but don't get lulled into a false sense of security (as you state "more than likely", that's not a 100% guarantee) with run-flat tires. They can be a tremendous help with a flat and provide safety and reassurance, but there are also drawbacks to run flat tires and I prefer to always have a spare. Most on the forum probably know or think of these things, but the average consumer buying any car with run flats probably hasn't given it a thought.
Run-flats in general:
Have a limited driving distance, 50miles at 50mph
Can have rougher rides do to stiff side walls
Reduced fuel economy because in general run flats are heavier/thicker
Be more expensive to replace, compared to non-RFTs
Can't always be repaired
Can leave a driver to stranded in case of side-wall failure or blow-out (since you won't have a spare)
Can leave you stranded in case of severe tire damage, i.e. shredded tire
I don't like the last 2 points as someone who's not afraid to change a tire or depend on AAA; caveat, I do a lot of highway driving for work. Not eliminating run-flats as an option, but don't assume there are no drawbacks. In general driving around in the city or near home you are fine, but do you want to be stuck on a highway in an unfamiliar location at 11pm with no spare when you have a run flat failure. I recognize a spare is not an option in the 45e, but I do like the security of it even if I never use it.