BMW X5 6 or 8 Speed?

[StreamSilver]

I am searching for the best BMW X5 diesel to tow my 25FB Signature (2013, 6-7k lbs). Currently, I tow it with a 2012 Touareg TDI 8 Speed. However, I will be selling the Touareg back to VW due to the diesel scandal. I had a hitch reinforcement on the Touareg from my Canadian friends at CanAm, and will do the same with the X5.

The questions:
2013 6 Speed Twin Turbo or 2014 8 Speed Turbo?
What features should I be on the lookout; wheel size, suspension, etc.?
What is the rev count on the 6 speed in 5th gear pulling 6-7k lbs?

-StreamSilver

[Road Ruler]

Good day StreamSilver.. Whatever one you get please post your towing experience. Interested in you feedback. Thnxs

[Isuzusweet]

If I were you I'd be looking at final drive ratio of the axle and transmission. Also consider torque fiqures as well. As for wheels, I would personally get the smaller rim size with a taller tire.

Personally I thinks it's six of one, half dozen of the other as for possible future problems. Turbos hate dirty oil, are not cheap to replace, and you have two on one and one on the other; however, the more speeds you have in your transmission, the more expensive to replace, with one having 8 versus 6 speeds (BTW you can't get parts for a BMW transmission). So whatever one you choose make sure you replace the oil beyond regularly (throw the maintenance minder out) and change the fluid in your transmission at regular intervals as well.

Fluids are cheap, turbos and transmissions.....not so much.

Cheers
Tony

[David F]

Originally Posted by Isuzusweet

If I were you I'd be looking at final drive ratio of the axle and transmission. Also consider torque fiqures as well. As for wheels, I would personally get the smaller rim size with a taller tire.

Personally I thinks it's six of one, half dozen of the other as for possible future problems. Turbos hate dirty oil, are not cheap to replace, and you have two on one and one on the other; however, the more speeds you have in your transmission, the more expensive to replace, with one having 8 versus 6 speeds (BTW you can't get parts for a BMW transmission). So whatever one you choose make sure you replace the oil beyond regularly (throw the maintenance minder out) and change the fluid in your transmission at regular intervals as well.

Fluids are cheap, turbos and transmissions.....not so much.

Cheers
Tony

Since when can you not get parts for a BMW transmission? I have rebuilt two "BMW" transmissions which are predominately manufactured by ZF and had no trouble sourcing rebuild kits and/or individual parts.

BTW, I don't think it matters between 6 or 8 speeds. Probably 8 speeds is best as there wont be as large of an RPM drop between gears. But, the trans may shift a lot on anything other than a level road. Sport mode usually solves that problem.

[dkottum]

I like the 8 speed transmission with our 3.0 turbodiesel Ram very much, especially when towing. Less engine rpm change from one gear to the next, hardly noticeable as you travel over the various grades of everyday roadways. None of the abrupt engine revs as the rpm drops and then shifts to the next lower gear.

As for tires, I like the lower profile tires best for stability with and without the Airstream, less sidewall wiggle. A little rougher ride though, Michelins smoother than the original Goodyear.

[jcl]

I would go with the newer model with the 8 speed ZF. BMW does not support many individual internal parts for these transmissions (they use exchange transmissions instead) but ZF parts distributors handle them all if it ever comes to a rebuild. 6 vs 8 isn't a big issue with the torque of the diesel, but the 8 speed would be nice towing.

It isn't just the number of turbos, they are different engines. The later engine might have been a cause for caution the first year of production, but check any service records available and see if there have been service issues on any particular vehicle you are looking at.

They are all low profile tires, relatively speaking. Sometimes the largest size can be disproportionately expensive at replacement time.

I would go for the later model F15 since it is on the same platform as the E70, but is one generation newer. That isn't just engine and transmission, but also ancillaries and electronics.

Jeff

[PKI]

The 6 is the E70 and the 8 is the F15. They are two very different vehicles.

Both will tow well as the diesel is a torque producing beast.

What is different is the steering, available options and OEM hitch. The F15 has no compatible OEM hitch - buy an aftermarket. The F15 has very sensitive steering. If you are used to tight steering, you will have the skills, but will still need to fine tune your input. If you are used to loose steering with significant mechanical feedback, you will need to calibrate your skills a bit. The late model Xs have some really nice safety options and that capability deserves consideration.

We did not purchase our X to tow. We wanted the safety features that BMW offered. It has turned out to be a very good platform, but not with the help of BMW. It takes a lot of research and outside help. Since you are headed to CanAm, most of those issues fade away. The potential impact to your warranty is the only issue that you should consider.

If I was facing this decision, I would likely look for an E70 in very good condition. Focus on getting a basic platform with air suspension, OEM hitch and lighting module installed, and 19in wheels. I think you will end up with 18s, but look for the lower profile solution. The exception is if you are an off road fanatic. Then go 18s. The reason is that there are not a lot of good stiff wall tires in the 55 aspect. Bumping up to 19 gets you a slightly lower profile and that stiffens up the side wall since there is less of it. The concept is counter intuitive and would be reversed if you were not towing. Also, get a spare tire. The run flats give you a stiffer side wall, but you can't tow on a flat run flat. You may even be able to justify a full size spare, but they take a lot of space.

Now, if you can't find a good E70, moving up to the F15 will be the solution. Better options, but higher cost. There are some coming off lease, but that is a mixed bag. However, you will love the 8-speed. There is also the option of looking at the Mercedes vehicles. Do not discount that alternative. And the Dodge Durango may be worth considering as well.

Fluids less expensive than parts? The concept is logical, but the 8-speed transmission fluid is lifetime rated. That is 100K which for a lease vehicle is great. For the folks who consider lifetime to be 300K and tow most of those miles, it is not so great. Quote was ~$2000 to change the transmission fluid. Seems more than excessive. More research on this is obviously needed. Can't believe there is not reasonably priced synthetic super fluid available that is compatible, ultra clean and ................. denial or reality, I don't know yet. Pat

[jcl]

Originally Posted by PKI

Quote was ~$2000 to change the transmission fluid. Seems more than excessive. More research on this is obviously needed. Can't believe there is not reasonably priced synthetic super fluid available that is compatible, ultra clean and ................. denial or reality, I don't know yet. Pat

http://www.thectsc.com.

Only use the correct original Lifeguard fluid for your specific transmission model.

[PKI]

Originally Posted by jcl

http://www.thectsc.com.

Only use the correct original Lifeguard fluid for your specific transmission model.

And thus, information is transferred. Thank you. Pat

[bono]

Another consideration is that BMW 35d E70 has two turbos diesel engine which was de-tuned for the US market to 265 HP (normally 289 HP). F15 35d is just a single turbo engine. I do not know whether it matters that much, but this was one of two reasons I did not opt to switch from E70 to F15 (the second reason is lack of steering wheel feedback on F15).

I am towing with 18 inches and 20 inches wheels. 20 inches provide a little bit more stable towing, but almost not noticeable.

[StreamSilver]

All,

Many thnx for the responses. This information is well received and in line with an email I received from CanAm today. I will certainly follow-up with information regarding the vehicle I choose and the towing experience it creates.

Now, if VW would get on the ball, I can sell the Touareg back for 120%., which is a crying shame. I like that vehicle.

-StreamSilver

[Isuzusweet]

Originally Posted by David F

Since when can you not get parts for a BMW transmission? I have rebuilt two "BMW" transmissions which are predominately manufactured by ZF and had no trouble sourcing rebuild kits and/or individual parts.

BTW, I don't think it matters between 6 or 8 speeds. Probably 8 speeds is best as there wont be as large of an RPM drop between gears. But, the trans may shift a lot on anything other than a level road. Sport mode usually solves that problem.

Someone on the news up had a BMW Mini transmission that gave up the ghost; couldn't get parts or rebuild kit for the tranny; had to purchase a whole new transmission from BMW that cost $7,500 CAN and another $4K to install with taxes.

I work at a Honda dealership and have seen first hand that modern day transmissions are so complex that even transmission shops are loath to work on them. I don't know of any shops that would take on a 9 sp Pilot transmission or a Honda CVT

Glad you found parts for yours, but sad to say, it is becoming harder to rebuild anything.

Cheers
Tony

[David F]

Originally Posted by jcl

http://www.thectsc.com.

Only use the correct original Lifeguard fluid for your specific transmission model.

Debatable...been using both Pentosin ATF-1 and Mercon SP for thousands of miles with no issues. It is well documented that Lifegaurd is not necessary. But, I change more often when using alternate less highly refined fluids that are less durable to temperature extremes

[jcl]

Originally Posted by David F

Debatable...been using both Pentosin ATF-1 and Mercon SP for thousands of miles with no issues. It is well documented that Lifegaurd is not necessary. But, I change more often when using alternate less highly refined fluids that are less durable to temperature extremes

Yes, I would agree that nearly anything is debatable.

The issue I have with the generic fluids is that they recommend a single fluid (such as Pentosin ATF-1) for any of the ZF automatics, whether 5, 6, or 8 speed versions. But BMW, and more importantly ZF, publish different fluid specs for each of those models. The transmissions aren't designed to use the same fluid.

Using a generic fluid is probably not an issue at all with an older model ZF, but with the newer models, it seems to me to be safer to go with the ZF spec. I wouldn't buy it from BMW, as they aren't very interested in selling fluid, but a ZF distributor would be a good choice.

Using a different fluid spec is no guarantee that one will have problems. But it seems to me that with the fluid being lifetime (or 8 years in heavy trailer towing applications, per ZF) that changing it early is really a risk mitigation strategy. If the intent is to reduce risk, using a non spec fluid would appear to be working against that strategy.

[jcl]

Back on the E70 vs F15 question....

The 8HP transmission has a higher torque rating than the 6HP transmission. And if you get the updated 8HP75 it is even higher. I haven't heard of a lot of transmission failures, but it would seem to me that if pulling a heavy load, the heaviest duty transmission would be worth putting on the wish list.

Jeff

[StreamSilver]

Hello all; I have buy back date with VW and a scheduled appointment with CanAm. Hope to be back on the road by August towing with a 2014 BMW X5 35d! Nice vehicles!

Quick question: Any advantage or disadvantage having Run Flat Tires while towing?

-StreamSilver

[PKI]

The sidewalls are stiffer, however, there is no clear consensus that this construction is of any viable comparison to the better stability of light truck tire construction. My logic, unconfirmed by any valid practical comparative experience is that stiffer is better than the more flexible side wall of non-run flat tires.

We run the 18s. If your vehicle has the 19 or 20 in wheels, going to the non-run flats may get you better ride with minimal degradation in towing stability due to the shorter sidewall. Have not found any info that would substantiate that opinion. Most RF vs NRF comparisons are ride and traction specific with no regard to tow applications.

It seems logical to keep as much tire running as possible in a tire failure event.

It is also not logical to assume a RF tire will survive deflation while towing. Expect to need to install a spare. Note the compact spares have to be installed on the front. They have a limited range and travel speed must be reduced. One user reported getting longer range by stopping periodically to let the tire cool down.

Currently considering replacement options to the OEM Goodyear RFs. Likely will go with RF again. Very tempted to got to Michelin Premier LTX, which are well rated for performance, but not RF. Likely will go with, Michelin Latitude Sport 3 ZP, but still looking.

Interested to see what folks say to your question. Pat

[MetalAria]

Hi all,

I pull a 23FB with a 2012 E70 - 20in wheels and OEM towing package. The 6-spd works nice for towing and everything is super stable on the road.



I haven't experienced a lot of shifting while towing, either. If you are concerned about it, you can switch it manual mode and control the shifting.

Either way I don't think you can go wrong. Enjoy!