4700 RPM all day on 5W20?

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Ironically, this is a good example of how high rpm can actually be beneficial. Consider what would happen if the gearing was taller, so that the engine was turning only 3000rpm at the same speed.

The power requirement would still be 71hp; that is how much power is needed to push the vehicle through the air regardless of how you do it.

The torque required to produce that horsepower would be different though. Plug the numbers into the horsepower = torque x rpm / 5250 equation, and it turns out the engine has to produce 124lb-ft of torque, or 50% more than before and up to 84% of this engine's maximum. Actually, at 3000rpm this engine probably doesn't produce that much torque, so it couldn't pull that gearing anyway, but it is an interesting example.

- Glenn
 
At 6000 ft you lose about 15% of available horsepower. However, it takes less power to push the vehicle through the air, and top speed isn't affected very much, nor is the percentage of power or torque required to maintain a certain speed. However, the absolute quantity of power and torque required goes DOWN, so it actually makes it easier on the oil the higher you go.

The only problem with that is that cooling airflow is also reduced. Not a problem at this time of year.

- Glenn
 
If it takes 71 BHP to push the car the stress is that of 71 BHP regardless if the engine can produce twice that at sea level, or just that because of the high altitude. No worry in my book.

aehaas
 
My Civic turns over about 4100RPM at 80MPH. I've driven pretty long stretches at sustained 80-85MPH on Mobil 1 5w20, no worries. If it couldn't handle it they wouldn't have geared it that way. I'd just try and vary the speed at least till you get a few hundred more miles on it.
 
I used to own a 1989 Mitsubishi Mirage Turbo with short gearing that turned around 4500rpm at 80mph, as I remember it. Recommended oil was 10w30. Never had an oil related problem.

Palut, when I drove Interstate15 through Montana and Idaho last spring, the posted speed limit was 75mph, day and night. Idaho State Police must have been sleeping when you drove through there at 100mph, because they gave me a ticket for doing 86mph.
 
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Palut, when I drove Interstate15 through Montana and Idaho last spring, the posted speed limit was 75mph, day and night. Idaho State Police must have been sleeping when you drove through there at 100mph, because they gave me a ticket for doing 86mph.

Montana got rid of its "Reasonable and Prudent" speed limit several years ago. I don't know how accurate this is, but I've read that when there was no posted daytime speed limit, traffic fatalities on Montana's freeways reached all time lows.

There was absolutely noone on the highway during my 100 mph stint, I was quite lucky. Unless you were in a winding mountain pass, or city, or something like that, your 86 mph ticket was bogus!!
 
Wow. 3k rpm is about 80 MPH in my Camaro.

Yeah, I'f go with M1, and maybe even throw in some VSOT. Keep an eye on the temp gauge. Check the oil level with every visit to the gas station or *** stop. You might consider taking a spare quart or two of oil with you for topoff.
 
No, I mean it's bogus now. Pretty much all of those flat, rural freeways with wide open space on both sides that currently have posted limits of 75, should, in my opinion, have only recommended speeds of 75, and recommended speeds for corners that can't be taken at high speed. The LIMITS should be 120 or 130, at least.

Many people will say that I'm crazy, but I truly believe it would be safer that way.
 
Ok, I thought you meant it was bogus in a different way. The "Reasonable and Prudent" speed limit was somewhat safer according to this, however, I wonder what the newer records show, I'll have to look them up. http://www.hwysafety.com/hwy_montana_2001.htm

Scion Xa runs 3100rpm@60mph, and 4100rpm@80mph, for some reference. Get's 30mpg at 80mph. Ofcourse it is only a 1.5L engine. Motortrend didn't note any oil consumption if the few hours it was driven at that speed.

bulwnkl, when you do end up making this trip, i'd be very interested in the mileage you get at that fairly high rpm.
 
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http://www.hwysafety.com/hwy_montana_2001.htm

This is a very good read. Most of my adult life I've been trying to educate the Speed Nazi's that the principle of highway safety have been known for many decades. But as usual, scam science and political correctness prevail and our populace gets indoctrinated with false truths.
 
You got that right 427Z06. The issue of speed limits is always 'clouded' by the presence or absence of Federal highway money as well...
 
A lot of stuff being posted here, but I'm wondering then...why does the "for sustained high speed driving" quote fall under the 'severe driving' column? And yet another reason why Europe has specs oils with some cojones.

I don't think 'flow' will help you worth a darn when the bearings are spinning at 7000rpm. You better have a 'cushion' of oil ie. viscosity there between the high-speed moving parts regardless of load.
 
Dr. T, are you suggesting that lightweight oils are excellent for conditions where the engine is operating at 5-10% of maximum output, but that somewhat heavier oils provide better protection when an engine is operating at 30-50% of maximum output on a sustained basis? Is this notion contrary to southern AZ proving-grounds work at higher speeds?
 
Regarding the current, and former, Montana speed limit,I've lived in Montana, and worked as a staff attorney for the Montana Legislature, since 1981. At the time that the feds imposed what was known as the "conservation speed limit", Montana's speed limit was that:

"A person operating or driving a vehicle of any character on a public highway of this state shall drive the vehicle in a careful and prudent manner and at a rate of speed no greater than is reasonable and proper under the conditions existing at the point of operation, taking into account the amount and character of traffic, condition of brakes, weight of vehicle, grade and width of highway, condition of surface, and freedom of obstruction to the view ahead. The person operating or driving the vehicle shall drive the vehicle so as not to unduly or unreasonably endanger the life, limb, property, or other rights of a person entitled to the use of the street or highway."

Montana went back to the above speed limit after the feds repealed the conservation speed limit law. There were two main reasons why Montana later, in 1999, got rid of the careful and prudent speed limit and adopted numerical speed limits. One was that the vast majority of Montanans were fed up with and felt endangered by the excessive speeds of a lot of drivers. You have no idea what it was like, unless you lived here. Even seasoned, hard and fast driving, born in Montana, get the government off my back, drivers, had had enough. The other reason was that we were tired of being pilloried, put down, and made fun of by the rest of the nation and its constant media news coverage of what they called our unlimited speed limit. The coverage rarely pointed out the actual wording of the careful and prudent law. It simply snidely portrayed Montana as a backward state having a law that let everyone drive as fast as they wanted, anywhere, at any time. Contrary to the claim of the study referred to in prior posts, the government officials who testified in favor of the bill TRULY DID support the bill, and were not just doing the Governor's bidding. The bill passed the Senate by a 48-2 vote and passed the House by a 73-27 vote, and one of the reasons for the lopsided votes was that the legislators were voting the wishes of their constituents, the vast majority of whom favored the bill. I was there, and I know what I'm talking about. That study, by the way, is suspect in other respects, not the least of which is that the obvious patent dislike of and prejudice toward government officials tips the reader off to the fact that the person(s) behind the study have both an agenda and an axe to grind. Such studies are always suspect, because they are always carried out in a manner designed to produce predetermined results. I've read hundreds of such studies in the course of my legislative work.

The kind of sustained, long distance, high speed, law-breaking, driving that bulwnkl is obviously contemplating, is not safe when engaged in by most drivers. Yes, of course, many drivers are capable of doing it safely. On the other hand, there are far too many kids, old people, hot dogs, poor drivers, distracted drivers, etc. that think they can drive at those high speeds in a manner that is safe for themselves and others when in fact they are deluding themselves and are a menace to themselves and others.

Am I the only one that finds it ironic that bulwnkl, who recently strongly attacked SUV's because of safety concerns, particularly for drivers of small vehicles, obviously believes that its ok for a person to take long trips (in a small vehicle by the way) at illegal high speeds with no apparent concern for their lawbreaking activity or for the safety hazards posed to others? I sure that hope he and an SUV don't collide.
 
Very well put jmacmaster. After almost 27 years of law enforcement all I can do is shake my head at the attitude displayed by some drivers.The term "spirited" driver and "agressive" driver are used proudly by posters here every week. The irony you pointed out in the SUV=bad, small speeding car=good is priceless. Thank you for saying it so well.
 
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...felt endangered by...
...tired of being pilloried, put down, and made fun of...

I think those are pretty much the reasons 427Z06 already stated. Don't bother to act on fact and engineering, just 'feel' your way into higher death rates.

I had hoped those in positions such as yours would be able to recognize the entirely different circumstances on city streets and intersections compared with open highways at speed. Though I'm not surprised they do not, it's still disappointing. Isn't it ironic how willing you are to legislate us into proven higher death rates, but so completely unwilling to entertain ways to lower them...
 
"Isn't it ironic how willing you are to legislate us into proven higher death rates, but so completely unwilling to entertain ways to lower them?"

And where is the proof that lowering highway speed limits increases highway deaths while an unlimited reasonable and prudent speed limit will decrease deaths? Those in this thread who have made this claim cannot rest on their mere assertion that this is the case. If they are going to make that claim and are called on it, then they should produce scientific, well-designed, and well-carried out studies by people who are independent and nonpartisan and seek only to get the true facts, not to produce a study that results in a predetermined result. The study mentioned in this thread is a joke. As I pointed out before, those who carried it out obviously have an agenda and an axe to grind, so the study is suspect. In addition, speed on the highway is the only factor that the study looked at, when in reality, speed on the highway is only ONE of many factors that must be looked at in determining the cause of highway deaths. You cannot simply say that the speed limit was lowered and deaths increased and therefore the lowering of the speed limit caused the deaths. There are far too many other factors involved and anyone familiar with truly scientific studies of a cause and effect nature knows that.

I don't legislate anything. I'm an employee of the Legislature and never get to vote in the legislature. The nature of my job requires me to be nonpartisan and neutral on all issues that I work on, for various excellent reasons that I won't take the time to go into. I have for 24 years been an expert in sifting through the info on an issue and determining what is based on fact and what is based on conjecture, what is based on a partisan viewpoint and is thus to be discounted, and what is produced in an attempt to get at the truth and let the chips fall where they may. The area I work the most in happens to be the criminal justice system, including traffic regs. I've done more than my share of work considering ways to lower deaths on the highways. From the considerable information that I've seen, from state and federal and local government agencies, lobbyists from various interest groups, private organizations, concerned citizens, and other interested parties and entities, an unlimited speed limit, so long as one drives in a reasonable, prudent, and careful manner, is not one of them.

"I had hoped those in positions such as yours would be able to recognize the entirely different circumstances on city streets and intersections compared with open highways at speed. Though I'm not surprised they do not, it's still disappointing".

Since you are also an employee of a state government, I'm surprised at the anti-government employee slant of this statement. You should know better, as I'm sure that you're as sick as I am of the widespread and unwarranted prejudice toward state government employees.
 
One other point to consider, when trying to justify high speeds. Do you have any idea of your chances, or those of your passengers, of surviving a tire blowout at any speed over 80 mph? Two - slim and none, and slim just left town.

Seriously, if you have a blowout, or mechanical malfunction, or hit an elk, whatever, at that rate of speed, on admittedly sparcely populated highways, what are your chances of getting timely help even if you did survive the initial event? You and your passengers would probably just lay there suffering until you died.

Leave a little earlier, drive reasonably - you'll live longer.
 
bulwnkl said:

"quote:
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...felt endangered by...
...tired of being pilloried, put down, and made fun of...
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I think those are pretty much the reasons 427Z06 already stated. Don't bother to act on fact and engineering, just 'feel' your way into higher death rates."

One of the reasons that I stated was why Montana went from the reasonable and prudent speed limit to specific numerical limits was that "the vast majority of Montanans were fed up with and felt endangered by the excessive speeds of a lot of drivers. You have no idea what it was like, unless you lived here. Even seasoned, hard and fast driving, born in Montana, get the government off my back, drivers had had enough."

The nation's foremost analyst of and expert on state legislatures once said that "legislative politics is really the only game for adults. All other games are for children".

The state government legislative process is extremely complex. It is designed to, among other things, allow all who wish to have a say on a bill that is before the legislature to say what they wish. The value of a person or entity's testimony or written submission of a statement varies widely. What is said runs the whole gamut from totally unsupported opinion, much of which is obviously prejudicial, to top quality studies and analysis. The way it works is that the people elect the legislators of their choice, at a legislative session the people can show up and testify on a bill, and the bill is studied, often amended to address peoples' concerns, and is either passed or rejected. This happens in each of the two houses of the Legislature, both in a committee of each house that hears the bill and when the house meets as a whole to consider a bill that gets out of the committee that worked on the bill.

There is no doubt that many bills are passed based largely, and sometimes wholly, on peoples' mere opinions, unsupported by facts, or based largely, and sometimes wholly, on mere anecdotal evidence. In my opinion, it is best if a law that is passed is supported by more than this. However, the opinions and anecdotal experiences of the people are not to be taken lightly. A lot of these people have been around, and know a lot, and know what they are talking about, and have much information to contribute. And it is their right to speak up. It is from them, after all, that we elect our legislators. Legislative politics can be a messy business. It is not perfect and is not the best system of government, but as is often said, it is better than any other that has been devised. There is no law mandating that a bill should only be passed if it is supported by top quality, nonpartisan, studies by experts in the field. In the real world of a legislative session, it just doesn't work that way and was not intended to by the founding fathers
 
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