As promised a while back, I now report the median mpg.
Mpg before atf change = 29(UK).
after " = 29.7(UK). 4 samples before, three after.
The conclusion is the slight improvement is likely to be warmer weather than anything else, not due to fluid change. The amazing fall in consumption must have been a 'blip/anomaly'; it was lifted from computer readout. Consistently now 29mpg (real) is logged by computer as 32mpg., something like a 9% error.

Re. the fluid change, it has been a big success. The only effect left is a very slight judder under heavy acceleration in gear 3. Otherwise, working correctly. After 120,000mile I have no complaints.

To remind, it's a 6HP26 autobox in 2006 S-type diesel, atf. used was Mobil full synth. meeting Dexron VI.
Leedsman.

 

Good to hear and yet another datapoint for Mobil 1 Syn ATF. I've about a dozen customers' 6 speed boxes out there now all running on Mobil 1, and over the last 2 1/2 years, including my own 6 speed in my X350.

 

How much do you typically pay for a quart of Mobil 1 synthetic ATF?

 

http://www.sparktecmotorsports.com/98hc69-gallon.html

$31.84 a gallon here, specs are listed as well.

 

I paid £66 for 8litre. Litre's about a quart, if a US quart is 2pint as it was in UK long time ago. 8litre's the most you'll want for a usual change, maybe 11 or 12 if you have special machine that blows it out via cooler lines. Use the additive (most important to get the stiction* in the clutches right) if you do the change the usual way, which leaves old fluid in torque converter. I used "Forte" with the accent on final 'e' at £14 for a little toothpaste tube-sized package.

*Stiction, or sticky-friction; the difference between stuck together friction and sliding friction. The difference has to be right for the various wet clutches in the box to work right without slurring or juddering.

Leedsman.

 

Hmmm, significantlly less than even the most favorable pricing that I've been able to dig up on the ZF Fluid. This may be worth adding to the list of potential ATF replacements once your car is post-warranty. Thanks for posting the link....

 

About $8 or $9 Jon. Just depending on where/who has it on sale, or regular price.

 

Thanks for psoting that!

What sort of mileage were they changed at and what have they done since, as far as you know?

 

Mine are ALL recommendations to my clients at about the 60K to 80K mileage range on average...or after warranty. Before warranty and in order to maintain it, you have to go along with the factory recommendations.

BTW, my preference is to go after a change right after 50K miles, but I've not been lucky enough to catch anyone right at that point.

I present to my clients the information about fluid types, both the factory recommended type brand and my recommendations. Then, once educated, I make them make the decision about which fluid they'll use (Mobil 1 or Lifeguard 6). They make the decision and accept any risks. To date, there have been no failures because of fluid types in any transmission I've serviced. I've only had two customers that insisted on the lifeguard 6. The rest all went with Mobil 1.

 

2 customers with money to burn. Mobil1 Synthetic is a very good ATF. Castrol Multi-Import Vehicle ATF was better then my 70k miles FF oil, but not as good as the Mobil1. I can wait to do another flush to get my Mobil1 ratio higher, right now I have about 5quarts of Mobil1 and the rest Castrol.

Oh and Mobil1 ATF is $7.50 here in Autozone.

 

What is FF oil? Is that a typo for ZF Fluid? Or is FF short for factory fill?

 

FF is Factory Fill. I should have clarified that, sowwwie

 

I really need to work on the acronym page.... H20 is going to kill me....

 

Thats cool, now your certain of it : thumbs up :