2007 x5 very harsh ride

[byaru1]

Originally Posted by bcredliner

Yes, MPG will decrease, wear will increase. Tire temp will also increase and handling will be compromised.

I don't notice any compromise in handling at 29psi.

When considering handling I think of the compromised capability to handle emergency situations and wet or slippery roads. X5 weighs over 5,000 pounds and has a high center of gravity. I expect that OP is looking for a longterm solution. Regardless, IMO, decreasing tire pressure should not be part of it.

Why not? It's not a significant decrease and it works. It's 3 years for me at 29psi on the same set of Kumhos.

I wouldn't change size of wheels either.

You are now being too careful and walking in eggshells Analysis paralysis..

Of course the tyre sizes can be played with within reasonable safety considerations.

I think the longterm solution will be a combination of tires that are well documented as a soft riding, comfort tire and changing shocks/struts.

For me, less tyre pressures have worked, and I can say long term.

[bcredliner]

Originally Posted by byaru1

I don't notice any compromise in handling at 29psi.


Why not? It's not a significant decrease and it works. It's 3 years for me at 29psi on the same set of Kumhos.




You are now being too careful and walking in eggshells Analysis paralysis..

Of course the tyre sizes can be played with within reasonable safety considerations.



For me, less tyre pressures have worked, and I can say long term.

One case is anecdotal. Glad you achieved what you wanted but your results cannot be assumed to be universal.

Nevertheless, if tires are under inflated the contact patch becomes smaller negatively impacting handling, traction on wet or slippery roads and braking distance. I see no reason to accept any increased risk when it comes to being as safe as possible when driving especially when there are other options to address the problem that don't increase the risk.

[andrewwynn]

Agreed on the minor change in psi.

Studies show that before tpms the majority of tires were under inflated more than 5psi though there is a chance some accidents were causes from it, the legislation that brought about TPMS requirement was based mostly on saving gas.

People that track their cars will adjust up and down for what they need and it is likely not related at all to the door jamb guidance.

It probably takes at least 6-8 psi drop to be a significant issue for handling, wear, temperature damage.

Most people will not noticed a difference in handling before 5psi change and 3-4 psi drop is not going to cause enough a problem with emergency handling.

Example math;
My car with 1200# and 33 psi 1200/33=36.364 in.² contact patch.

Drop that psi to 29 : 1200/29=41.379 in.².

5 in.² difference would likely be enough to be difference in snow not too likely to be a problem otherwise.

[andrewwynn]

You can't know what will happen to contact patch or roll : Cg body roll without actual testing.

In general the only way to know what the proper inflation for your exact tire/car is will be experimentation and watching your tire wear.

I know that with Dunlop grandtrek M3 RF tires I will get edge wear = under inflated at 32. I now use 33-34 to counteract that and I haven't driven enough miles to see any wear at all yet much less more wear center or edge.

When Ford had a huge problem with explorers rolling over, the "fix" was to change OEM tires and add a couple psi to the door jamb recommendation.

That said, there is a lot of safety margin; plenty to account for 3psi drop over base recommended.

I personally would look for a better set of taller ratio non RFT tires then if that's not enough knock down the psi a little bit.

[bcredliner]

Originally Posted by andrewwynn

You can't know what will happen to contact patch or roll : Cg body roll without actual testing.

In general the only way to know what the proper inflation for your exact tire/car is will be experimentation and watching your tire wear.

I know that with Dunlop grandtrek M3 RF tires I will get edge wear = under inflated at 32. I now use 33-34 to counteract that and I haven't driven enough miles to see any wear at all yet much less more wear center or edge.

When Ford had a huge problem with explorers rolling over, the "fix" was to change OEM tires and add a couple psi to the door jamb recommendation.

That said, there is a lot of safety margin; plenty to account for 3psi drop over base recommended.

I personally would look for a better set of taller ratio non RFT tires then if that's not enough knock down the psi a little bit.

Of course one won't know what will happen based on inflation changes without some testing. That's the point. You won't know until you drive beyond the limitations of the suspension, ones talent and the tires. Yes, there is some tell from reading tire wear but that doesn't tell you what will happen when pushed to the max. I always have inside wear on my tires. They are properly inflated. The wear is from the max highway handling alignment specs I use and how hard I drive.

My bet is the OEM tire Ford changed to had higher inflation specs established by the MFG. It might have been wider or lower profile also. The Ford problem is an example of even a MFG. with extensive testing capacity that doesn't get it right. I agree there is some wiggle room for inflation. Lawyers would insist they is.

I'm sure you were using the M3 as an example of what happens with your M3 rather than comparing it to what happens on an X5 as comparisons of what happens with other vehicles is directional at best for an X5.

What happens to the overall handling of a vehicle depends on the capability of the driver, the tire and the road at that particular time. One can't set the parameters for an emergency situation.

I agree that if one chooses to improve ride with tires, the best route is a taller sidewall, a tire known for soft and quiet ride, that is not a run flat and inflated within the specs. I don't know how much is a little bit to you. Base on track experience, not with an X5, 1 pound makes a big difference to handling. I have no idea what the number is for an X5.

[andrewwynn]

I notice a difference in road handing on my X5 when I lose 2-3# from ambient


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[bcredliner]

One way to get a sense of how sensitive a vehicle is to air pressure reduction is to drop air pressure in one front tire by 3psi and take a drive. The vehicle will pull toward the soft tire when one lets go of the steering wheel.

[andrewwynn]

That's very true.

[e70jane]

Originally Posted by leafsrule531

I have a 2007 e70 x5 3.0 with 3rd row seating. The car doesn’t have air suspension. I just recently did a whole suspension revamp in the hopes that my ride would get smoother / softer. This includes Sachs shocks and struts, new bump stops, strut mounts, control arms, end links for the front and I even got rid of the run flat tires and put regular Michelin tires.

Now I do admit that I live in NJ and a do lot of driving in NY and the roads are horrible. But I cannot come to terms with the fact that Bmw made this suv so harsh from the factory. The car does have 140k miles on it but I would’ve thought that after doing a suspension revamp the car would’ve been driving like new. It’s not even enjoyable to drive this car with passengers in the back. It’s to the point where some people in the back feel nauseous at how bumpy the ride is with almost no give up on the ride. I’ve driven Bmws all my life and also own an e46 m3, 330ci, e90 with sport suspension so I know that these cars are built to be sporty and a focus on handling. But the x5 just has a horrible ride - there is no smoothness in the car at all.

I wanted to get others opinions on this ? Does everyone’s x5 with no air suspension drive this harsh ? Have I missed anything that I should replace that would improve this ?

Should I just get rid of the car Ans get a Lexus ? I really don’t want to do this since I’ve spent so much money on maintenance already on this car.

Would love to get any advice or feed back!


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07 e70 4.8 55k miles and I too feel the same way lol. They’re extremely heavy so there’s no real way to soften the ride other than keeping the stock 19’s with thicker sidewall, that’s it. I’ve got 20x10.5 and 20x9.5 factory wheels in addition to h&r springs and it’s bumpy as hell. I’m actually thinking about raising it back up. Mine came with rear air bags only. e70’s don’t have airbags on all 4 corners, only rears. If you want a nice smooth ride and a full size suv, Lexus is a good choice.

[byaru1]

Originally Posted by e70jane

If you want a nice smooth ride and a full size suv, Lexus is a good choice.

Recommending a Lexus on a BMW forum