RP Max ATF for Mercon V application?

[dogememe]

The Vic takes Mercon V but I'm thinking of using Royal Purple Max ATF. The first time, I would drop the pan and change the filter as well, after that I will be just doing drain&fills every 30K miles since I will be installing a pan with a drain plug. Any feedback on how RP Max ATF will work in a 2007 CVPI? I'm asking because RP Max ATF is like Valvoline Maxlife ATF in that it meets a hundred different specs, only thing is Maxlife meets LV and Max ATF doesn't, so I'm assuming Max ATF is thicker, which I think is good, right?

 

[VeryNoisyPoet]

Should work, as the specs list Mercon V as a suitable application.

Max ATF specs show 38 cSt @ 40C and 7.5 cSt @ 100C
Maxlife specs show 29 cSt @ 40C and 5.9 cSt @ 100C

Thicker ATF might lower the converter stall rpm a little. Thinner ATF might raise the stall rpm a little. My converter feels a bit looser with Maxlife vs generic Dex/Merc . Thicker ATF will have slightly higher pumping losses, and might cause a fraction of a percent lower fuel economy vs a thin ATF. Either will provide excellent performance and protection for your transmission.

If the current fluid is quite old, a triple drain and fill or a flush by unhooking the cooler line and letting it pump out would be wise.

Whatever you choose, I would suggest a UOA at the first drain and again at the next one 30k miles out to see how things are doing.

 

[dogememe]

Originally Posted By: VeryNoisyPoet
Should work, as the specs list Mercon V as a suitable application.

Max ATF specs show 38 cSt @ 40C and 7.5 cSt @ 100C
Maxlife specs show 29 cSt @ 40C and 5.9 cSt @ 100C

Thicker ATF might lower the converter stall rpm a little. Thinner ATF might raise the stall rpm a little. My converter feels a bit looser with Maxlife vs generic Dex/Merc . Thicker ATF will have slightly higher pumping losses, and might cause a fraction of a percent lower fuel economy vs a thin ATF. Either will provide excellent performance and protection for your transmission.

If the current fluid is quite old, a triple drain and fill or a flush by unhooking the cooler line and letting it pump out would be wise.

Whatever you choose, I would suggest a UOA at the first drain and again at the next one 30k miles out to see how things are doing.


Very interesting you mention torque converter stall RPM. Both crown vics I've owned (99 civilian model and now the 07 P71) have had very loose feeling torque converters off idle, and if Max ATF helps with that, I'd be thrilled. As for fuel economy, in theory wouldn't thicker fluid give less slippage and thus it would pretty much even out?

 

[VeryNoisyPoet]

It was a very slight change for me, maybe a couple hundred RPM or so. Worked out well since it gives the turbo more exhaust to work with

Maxlife may make your Vic's converter feel a bit looser, while RP Max ATF will probably keep a similar feeling to the original Mercon V. This also depends on the temp it runs at. Maxlife is 26% less viscous at 40C, but only 21% less viscous at 100C. However, at -40C, Maxlife has a Brookfield viscosity of 10,200, while Max ATF has it listed as 7950.

 

[dogememe]

Originally Posted By: VeryNoisyPoet
It was a very slight change for me, maybe a couple hundred RPM or so. Worked out well since it gives the turbo more exhaust to work with

Maxlife may make your Vic's converter feel a bit looser, while RP Max ATF will probably keep a similar feeling to the original Mercon V. This also depends on the temp it runs at. Maxlife is 26% less viscous at 40C, but only 21% less viscous at 100C. However, at -40C, Maxlife has a Brookfield viscosity of 10,200, while Max ATF has it listed as 7950.





Well I don't intend to drive my car anywhere below freezing so I should be OK

 

[pbm]

I know you didn't ask so ignore if you prefer.....but I would use any Mercon V ATF, including ST from Walmart, if I was changing it every 30K. At $15 a quart the RP would get expensive and probably have little benefit....if you planned on running it for 60 or 70K the RP might be worth it.

 

[dogememe]

Originally Posted By: pbm
I know you didn't ask so ignore if you prefer.....but I would use any Mercon V ATF, including ST from Walmart, if I was changing it every 30K. At $15 a quart the RP would get expensive and probably have little benefit....if you planned on running it for 60 or 70K the RP might be worth it.


Well, with drain and fills I don't get everything out, I'm not going to do a flush. I know there are plenty of cheaper fluids out there that would work totally fine in my vehicle, including Motorcraft Mercon V, but I'm not interested in them.