X5 towing experience and fuel economy

[Thecastle]

With that much weight the trailer should have brakes. Most states require trailer brakes for trailers greater than 3500-4500lbs. I've towed that much 5K without trailer brakes on my X5M, and it hardly notices it. That fuel economy seems about right for an open air trailer and car. Expect less the bigger the trailer.

[dennisvab]

But I have to say, that air suspension is nice!! I wasn’t complaining about the fuel economy, merely stating the facts. I believe the U-Haul trailer should have surge brakes. i don’t know if they worked. I just know that I had to give myself more room to brake.

[bono]

You were brave towing uhaul trailer @75 mph. Did you check the speed rating of the tires? I expect they were rated to max 65 mph.

[snik]

Uhaul trailers suck.


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[Thecastle]

Originally Posted by dennisvab

But I have to say, that air suspension is nice!! I wasn’t complaining about the fuel economy, merely stating the facts. I believe the U-Haul trailer should have surge brakes. i don’t know if they worked. I just know that I had to give myself more room to brake.

Agreed, self leveling suspension is great!

The one issue I've noticed though is it can mask any visual indicators of overloading the car. I had a recent trip to Colorado where I had about 850lbs+ of tongue weight with a weight distribution hitch. The rear of the car doesn't sag, but I know I overloaded the rear axle when I hit the scales and measured about 4K lbs on the rear axle (max rating is 3.5K).

[bono]

My observation is that when you need air suspension due to sag, you actually need weight distribution and then you may not need air suspension.

[bono]

Forgot to add... This is not even due to rear axle overload (axle has safty margin built in) but due to light front axle and problems with handling / braking.

[dennisvab]

It was definitely iffy to drive 75. I wouldn’t suggest that. As far as tongue weight. I would think I had more than 600 lbs in there. With the way the U-Haul trailer is set up, more weight is shifted to the front of the trailer.

[spyro235]

Originally Posted by bfeng

MPG: my diesel x5 got 14-16mpg towing an enclosed v-nose at nearly 9k lbs. pulling a flat nose enclosed at6k lbs I only get 12.5mph.

You towed an enclosed Vnose that weighed 9k lbs? What kind of tongue weight were you pulling with? Do you have the air suspension in the rear, and what hitch setup do you use? That's way overweight for the ratings, but how'd it do?

[bfeng]

Originally Posted by bono

You were brave towing uhaul trailer @75 mph. Did you check the speed rating of the tires? I expect they were rated to max 65 mph.

If the trailer has a speed max printed on it, you may get pulled over and ticketed. I got pulled over but let go with just a warning once (pulling a small 5x8 with an F150) and that was enough to make me slow down when pulling a Uhaul trailer.