should i raise up a grade in this climates summers

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Imo,if a car has to have a computer to cut it off if oil temp gets dangerously hot (because it's too thin),that's proof right there that thin oil = economy and thick oil = protection. I'd rather have thicker oil than some computer that can and will one day malfunction.

I wonder if that's why so many entry level current 5.0 Mustangs kept blowing engines when people would drive them hard?
 
Originally Posted By: OVERKILL
Originally Posted By: WANG

The Track Pack and Boss 302 are presumably geared toward track days. It makes sense for the owner's manual to specify oil suitable for that application.


But they ONLY specify 5w-50. They do not recommend 5w-20 (like what is spec'd for the regular GT) when driven "normally".

Originally Posted By: WANG
All I am trying to convey is, if there is a viscosity requirement for a long and happy service life it is probably spelled out in the owner's manual.


Unless it can't be.

Originally Posted By: WANG
The citations that people have provided of "Track Pack" and "sustained high speed operation" and etc., are examples of what I'm saying. If there is a better recommendation, it's probably in the manual.

In the case of OP's cars, there was no such recommendation germane to his operating environment, that he made known to BITOG.


But that's exactly the point. The Mustang GT, which CAN and certainly HAS seen track duty, spec's 5w-20 and gives no options for anything above and beyond that. In fact Ford has thermal castration mechanisms in place to ensure it doesn't lunch itself if oil temps get high enough due to the spec'ing of a single grade for that car regardless of ambient or operating conditions.

However, you buy the same car but with the "Track Pack" options pack and all of a sudden you have an oil cooler and a 5w-50 requirement and don't run into the thermal castration mechanism.


I will conceed ignorance to this characteristic of Mustang GTs. This is a pretty solid example where, in the case of non Track Pack GTs, the owner's manual recommended oil does not offer adequate protection up to the maximum performance available from that engine. However, I have to wonder how many owners found themselves in a "reduced power mode" outside of a closed circuit due to elevated oil temperatures. I would also say that the difference between "adequate protection" and "inadequate protection" with respect to plain bearings is most likely the difference between catastrophic failure and continued service. There isn't a ton of middle ground.
Again, I was ignorant of this aspect of Mustang GT operating characteristics, and it is a compelling case for the owner's manual not necessarily making consideration for all possible operating circumstances of a motor vehicle. I wouldn't have expected that.

However, for the great great majority of the vehicle operating public, some guy going 10-15 mph over the speed limit in his Corolla in the middle of summer (I don't really care where) isn't likely to touch or come close to these limitations.

I would say that we are taking the OP out of context, but I pointed to the owner's manual as the best source of viscosity guidance under any operating conditions. Overkill pointed out a case where maximum engine performance wasn't available for extended periods of time using the only recommended oil in the owner's manual (Coyote Mustang GT), so that is a fair point of discussion.

If anyone has a similar example of engines/powertrains going into "limp" or "reduced power" mode due to excessive engine oil temperature, let us hear of them:
 
So, my car was specd for 5w30. The eengineers designed it said: "go 5e30". A few years late the backspeced to 5w20. Not the original thinking anymore to take the competition on endurance. So now, the competition are 5w20, we gonna back spec it too,

BECAUSE IT'S STILL "ADEQUATE" (for the light footer, not to incentivated the gas guzzlers, those need to be banned the car and it driver's financea)

I don't buy it!
 
Originally Posted By: Pontual
So, my car was specd for 5w30. The engineers designed it said: "go 5w30". A few years late the backspeced to 5w20. Not the original thinking anymore to take the competition on endurance. So now, the competition are 5w20, we gonna back spec it too,

BECAUSE IT'S STILL "ADEQUATE" (for the light footer, not to incentivated the gas guzzlers, those need to be banned the car and it driver's financea)

I don't buy it!

First, they tested the engine with 5W30 at the time they designed it. They then tested it with xW20 some years later probably to improve gas mileage.

Some car companies like Toyota, Honda, Ford ... are concerning about reliability of their cars more than 0.2-0.5 MPG improvement with thinner oil. They have money and time to verify that xW20 is good for engines previously tested with xW30, that why they recommended it.

Remember that car companies like Toyota, Honda ... are selling millions vehicles a year, taking in tens of billions dollar in revenue, their reputations is more importance than almost anything else, especially their best selling cars such as Camry, Corolla, Accord, Civic ... they would not ruin their names to get 0.5 MPG gain with thinner oil if it causes their engines failed after 200-300k miles.

Remember that it takes many many years to built reputation and only few bad examples to destroy it.
 
First, how do you know they didn't test with xw20 in that time? There was a bunch of 20 weights to sell even in the 50's FYI. Synthetics 5w20 was the 1st Mobil 1 to be sold by the year 1975. Do you think 20 weights are new stuff? My oldest car is 15 years old, nothing less than a SJ era, those are still current as of last year.
 
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Originally Posted By: Shannow
Toyota 86/Subie BRZ have the same "feature"...some on here describe it as a wanted, desirable engineering feature to have the engine pull power within the engine's operational performance envelope.

7 dyno pulls, with a minute break between them isn't that extreme a workout.

http://blog.perrinperformance.com/brzfr-s-part-proving-all-bolt-ons-part-1/


Nissan 370Z also has it. It makes you run below 4k rpms for 5 min+ reiterately, to cool things down.
 
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It would be a nice touch if NASCAR had some input on oil temps and so on so we all could get a goods nice sleep and not stay up all night worry about oil temps....
 
Originally Posted By: ronp
Hi, been enjoying these forums. Have followed for a couple years now and just recently joined.

Anyway, the speed limit around here is 75 on the highways which i spend hours driving on through the week at 80mph usually.

This is also one of the hottest parts of Texas. Texas is as a state average is the 2nd hottest state in summer and fourth throughout the remainder of the year. I also live about 3 hours sw of Houston which the 2nd most humid city in the US.
So I drive fast for long periods most days in a very hot humid environment in summertime.
My cars spec a 20 wt. Truck a 30. Could it be necessary to raise a weight in summer for my situation? Is a20 weight really protecting my engines well enough?


Welcome to BITOG ronp! We would suggest that you stick with the oil viscosity that is recommended by your OEM – especially if you’re running all those highway miles as you described. While driving in the conditions you described, the temperature of your engine should be pretty steady. In fact, the highway miles that you describe are the best miles for a vehicle. Conversely, it’s the stop-and-go/short-route driving that kills an oil quicker than highway miles. You wouldn’t want to risk going too thick with your oil choice because it may compromise the oil flow characteristics that your OEM is counting on. An oil that’s too thick might not get to where it needs to be quick enough, etc. With that said, Pennzoil Ultra Platinum Full Synthetic motor oils would be a great choice for your vehicle. Hope this info helps! – The Pennzoil Team
 
No doubt that's the recommendation, as if something other than the CAFE oils were suggested, "the P team" would likely receive a invite to Federal Court...
 
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