Any changes or new data for or against TGMO 0w20?

[arluk3]

I bought a new 2017 Rav4 and changed the oil at 1,300 miles, using Mobil 1 synthetic Mobil 1 Advanced Fuel Economy 0w20. I observed a small amount of tiny metal shavings in the discarded oil. With the factory oil, I was getting gas mileage as high as 51 mpg on the freeway (!) and typically more than 35 mpg. With the oil change, it dropped to 30 mpg.

 

[PimTac]

The Mobil 1 Advanced Fuel Economy oil is some pretty good stuff. Since your RAV4 is still breaking in, your gas mileage will fluctuate. 51mpg is pretty high. Is this the hybrid?

 

[SonofJoe]

I've posted my thoughts on TGMO on a previous thread...

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4392658/23

I can't be 100% sure but I suspect TGMO contains a high SSI Poly-Methacrylate (PMA) VII polymer. This, together with the very high level of Moly, would make it a superb fuel economy oil. It's all explained in this presentation...

http://slideplayer.com/slide/7573500/

However there are very obvious drawbacks to formulating oils in this way. The PMA VII most likely used is highly shearable and notoriously poor in terms of HTHS. It also puts a disproportionately high amount of rubber in the oil and you might justifiably ask what impact that has on piston deposits. Finally I might question what exactly is the effect of all that Moly on the various seals used in your engine. Most Molys (thio-carbamates and the like) contain nitrogen which can be particularly aggressive to fluor-elastomers like Viton.

 

[PimTac]

SonofJoe,

Have you heard of any recent changes to TGMO? I ask because I get the impression that moly is being reduced in many oils. A recent UOA here with Toyota's Syn Blend 5w-20 showed no moly at all. In fact it had titanium. With many oils being reformulated for the updated dexos gen2 certification, I suspect that is the reason.

Interesting explanation in TGMO, in that solving one issue brings up another. Whack-A-Mole in reality.

 

[SonofJoe]

Originally Posted By: PimTac
SonofJoe,

Have you heard of any recent changes to TGMO? I ask because I get the impression that moly is being reduced in many oils. A recent UOA here with Toyota's Syn Blend 5w-20 showed no moly at all. In fact it had titanium. With many oils being reformulated for the updated dexos gen2 certification, I suspect that is the reason.

Interesting explanation in TGMO, in that solving one issue brings up another. Whack-A-Mole in reality.



I'm out of the loop now so TGMO could well have changed and I wouldn't have heard of it.

I'm surprised that anyone would replace Moly with Titanium. Considering I was present at its moment of conception, I have to confess I was never a great fan of the fruits of my intellectual loins! In the many years that have elapsed, I've come to regard Titanium as rather like our current Foreign Secretary, Boris Johnson; instantly recognisable, always being talked about but over promoted and fundamentally unsound...

 

[edwardh1]

so the answer is?

 

[fdcg27]

While there is no definitive answer, it appears that there are better choices than TGMO, as I originally wrote earlier in this thread.

 

[arluk3]

I do not have the hybrid, and 51 mpg almost seems impossible. I was getting the high mpg readings from my instrument panel, where the "average since last start" is displayed as a running average. At first I didn't trust it, getting 32 mpg indicated while going up and over a 4,000 foot pass several times from sea level, but the gas pump confirmed that number. When I got higher numbers, 35-51 mpg on freeway, I quickly ruined the overall average by doing some city driving, so I never got that high a number at the pump. I do trust the indicated mpg, though, while driving. Since I changed from the factory fill, I never get the high numbers anymore.