2020 Toyota GR Supra Revealed!

[LancePower]

Originally Posted by gymratter

some people are having their engines replaced or just opting for a buyback.

Are they replacing it with an identical engine? If so, what's the point?

[gymratter]

Originally Posted by LancePower

Are they replacing it with an identical engine? If so, what's the point?

im not sure. the guy on our sister forum wasnt specific. but maybe not all B58Ds are faulty.

[Yoshoobaroo]

Originally Posted by LancePower

Are they replacing it with an identical engine? If so, what's the point?

TL;DR: it solves the problem because statistics.

In mass production, you have a very very small chance of getting an engine where the tolerances and clearances end up at a close to worst case scenario. The chance is very small, but when you make enough of them it WILL happen. This can lead to clearances being too tight to provide proper lubrication, or on the other side of the spectrum, clearances are too loose so you lose oil through places you're not supposed to.

Most manufacturers will base their statistical analysis on a 3sigma-6sigma spread and tolerance their parts/assemblies accordingly. (look up 3sigma normal distribution for more info)

This means that at 3sigma (99.7% confidence interval) up to 0.3% of assemblies can be outside of acceptable tolerances. At 6sigma it's down to 0.0000002%. To make 6sigma work requires extremely tight tolerances and isn't really feasible on something as complex as an ICE, so 3 Sigma is likely what they use. I could be wrong, the germans may use something more precise, I'm approximating here. This doesn't mean that 0.3% of engines produced have oil burn issues, since only the ones that are on the loose side will lose oil, the ones on the tight side will not. Those may have different issues, but that beyond our scope here. So worst case scenario for a 3sigma approach, 0.15% of cars have an engine that burns oil.

Replacing it with an 'identical' engine, statistically, essentially solves the problem: if you replace the 0.15% of problem assemblies with a random sample of new ones, your problem assemblies go down from 0.15% to 0.15% of 0.15%, that's 0.0000023%.

Year/ sold/ Problem cars/ problem cars after replacing engines
2019/ 2884/ 4.3/ 0.006
2020/ 5887/ 8.8/ 0.013
2021/ 0897/ 1.3/ 0.002

total/ 9668/ 14.5/ 0.02


looking at the ~10000 Supras sold in the US so far, after the engine replacements on ~15 cars, you end up with 0.02 cars that still may have a problem. Keep in mind this is assuming ALL engines outside of the acceptable range will develop the problem, which they won't. 15 cars may not sound like a lot out of 10000, but these days with forums and social media it's enough to give a brand or model a bad name, so manufacturers pay attention and some are very proactive to fix these cars. Toyota, being known for reliability, should be one of those.

[strat61caster]

Originally Posted by Transport3r

Toyota must have busted BMW’s balls there. BMW considers 1liter/1000 miles normal.

That said I’ve never had a BMW that burned a noticeable amount of oil.

According to my Toyota owners manual 1L/600 miles is when you start having to fix things.

[beltax90]

oil consumption solution would be to swap a v10 into it. surprised no one has mentioned this yet..

[Transport3r]

Originally Posted by beltax90

oil consumption solution would be to swap a v10 into it. surprised no one has mentioned this yet..

LFA V10 would be epic.

[gymratter]

another one with oil issue.

[LancePower]

He must have one of the 14.5 cars that will experience oil consumption issues.

[gymratter]

[blackhawkdown]

This is blown up too much like the IMs bearings in the old Porsche. Oil consumption is normal in all engines, especially European engines. Supra engines use 0w-20 oil. I call it mpg oil. They need to swap it out for some heavier oil.

I still love my Supra. I just installed my Maxton lip spoiler.




Sent from my iPhone using Tapatalk

[Swift]

I wont quote the few posts above, however in regards to Sigma/data statistics, if today's manufacturer can't hold plus/minus .001" they are doing something wrong. My guess is the oil control ring/rings are to weak. Subaru has this problem in many of their engines because they want to run the thin oil while having as little as friction as possible to maximize MPG! They went so far as to replace the rings with different ones after 2015 in Legacy models and others...still have our issues especially if downshifting during spirited driving.

[beltax90]

[ZDan]

Originally Posted by blackhawkdown

This is blown up too much like the IMs bearings in the old Porsche.

IMS issue wasn't overblown. Thousands of destroyed engine, Porsche had to be taken to court, where they lost. 8% failure rate on the small singlerow bearing design used from 2000-2005. 8%, is HUGE. Exceedingly stupid design...

At least if you do have overconsumption of oil, you can continually add oil and not have the engine self-destruct! I'd call this Supra problem WAY more benign...

[gymratter]

sounds like they will have a fix soon