I have three quarts of RP in my trunk, and I can't feel any difference at all in my shifting.

Seriously, though, I am not an experimenter when it comes to most aspects of this car. I let other people do that. So, the good thing is I've missed all the bandwagons: FM, cocktails, MTL, and so on.

From a pure specs comparison, it makes more sense to me to run MT-90 than MTL, but let's face it: Everything I know about MTX fluid I've learned in the last month. Like I said, I'm not one to experiment.

Anyway, I don't have much to go on, here. I posted a response from RP, and I read the responses from Redline, and they both say nearly the same thing. RP inspires a bit more confidence, because they 1) knew what an MTX 75 was, 2) claimed to have "tested" their product in this exact unit, and 3) have enough confidence themselves to cross-reference their product with the XT-M5-QS. The Redline response seems rooted more on what should "theoretically" be OK, unless I read it wrong. Redline doesn't make as bold or specific a claim as RP wrt suitability, either.

Still, there's a lot we don't know about the RP product, and both RP emails are selectively vague about test methodology. What is the test? "No Italians are complaining, so it must be good?"

As TH has said, there could be a quality control issue with the MTL. Based on specs, the MTL should be fine. The MT-90 perhaps "better." Fram oil filters meet specs, too, and thousands of people run them without ever noticing anything wrong. If the quality of the MTL is inconsistent, that could explain a lot. (Doesn't prove it's true, though.)

I'm not interested in "like butter" observations, either. I could put straight ATF in there tomorrow and it would probably shift "like butter" compared to now, (with almost 75k on the original fluid!). My fluid needs changed, and I'm tentatively convinced that the RP is a good product with reliable quality, and that it might even work better than the Ford fluid. But, like I said, I don't have a lot to go on.


Function before fashion. '96 Contour SE "Toss the Contour into a corner, and it's as easy to catch as a softball thrown by a preschooler." -Edmunds, 1998