My acura service rep said frequent oil changes were unnecessary since our engines were aluminum and don't get as hot as the iron ones. He said 7500 miles changes were fine. Anyone know anything about aluminum vs. cast iron re heat.

 

run run run from this place

 

Yup, when they are running they generate the same amount of heat. I'd never go back to that place again!!!!!

Follow the recommended change schedule in your manual.

 

Maybe I misunderstood him and he actually said the aluminum HANDLES the heat better than the cast iron. Does that make a difference?

 

Just follow the manual, and you'll be fine..

 

I think that there is truth that the aluminum engines will HANDLE the heat better than the iron ones. And 7500 miles is not too unheard of for regular oil changes because there is less likely to be severe breakdown of the oil. Under normal driving conditions, the manual even states that 7500mi is ok.

About 20 years ago, we had the same 3000mi oil change interval. We've had advances in the production and material properties of engines to better withstand heat and wear and friction, advances in motor oil performance, etc. etc. What advantages did these advances provide if we are still at 3000mi oil change intervals?

But then again, the way some of you drive, you might as well keep changing your SYNTHETIC oils at 3000 miles!

 

don't ferget the initial break-in oil...back in the 50's/60's and maybe the early 70's, they had a 100-500 mile break-in oil to flush the system of any metal flakes lying around in the engine

 

I was told by the dealer to change the oil at 3750 intervals

 

I change at every 5K miles with mobil 1 syn 5w-20.

 

and he insisted that you do it at his place, right?

My dealer gave me a booklet with the service in it, and the changes were all at 3750 miles (dealer's booklet). The Acura manual though gives you two intervals depending on severe or normal driving.

I think it is a very safe bet (too safe) to always go by the severe schedule, as most dealers recommend. Of course, they want you to change more and also at their shops so they make moeny.

But with todays oils and engines, I'm willing to bet that even if you are close to the severe driving style, you can still change dyno oil at 5000mi. and not have a problem. That is how cars with oil/filter monitors can go up to 10k miles under more or less normal driving before requiring a change.

But it is YOUR car, YOUR money, and YOUR peace of mind.

 

Weird, my dealer also said that very same thing. I guess I'll stay at 3750 for piece of mind since it looks dirt at that mileage even if still is effective.

 

5000 is the best compromise between the 3750 and 7000 interval. I use redline 5w30 and my dealer does the oil change for about $20.

 

my dealer said 3750 as well, and i've been going to cerritos acura for the last 5 years. the 3750 number was the same number they told me on my integra. i think that's a good number. it's in the middle between the normal 7500.

and if you do a lot of commuting to work, stop and go driving, it's worth it to prolong the life of the car.

 

Doesn't the manual SAY to change it every 7500 miles? There is your answer!

If you feel that you want to change it more often then it will only be better for your car, worse for your wallet.

According to the dealership, they recommend 3750miles in harsh weather conditions like we have in Boston. I still think it is a crock of sh!t and plan to change every 5000 miles or 7500 if I am lazy. I wouldn't go over 7500 personally though.

 

The manual says 3,750 and 7,500. Depends on the environment and the type of driving you do. I think it's too easy to be placed in the severe case, but that's just my opinion.. YMMV

 

Then again you are paying what? $8 a quart for your Redline? Time to change your oil and filter, >10 mins, So, he is in fact charging you around 150/hour. Not such a good deal anymore huh!?!

 

Is it possible to change the oil too often?

 

FYI...i pay $7.86 a quart! So ha! .

 

Damn...how much you pay for your oil filter? It's not one of those cheap Honda ones is it???? It better be those high grade Acura ones straight from Ohio.

 

With amsoil they say u can do it twice a year for an oil change. But then u have install their double filter and extended size ones. And a few other little items. But i heard some good stuff about it even at twice a year old changes.

 

I was told 3,750 by my dealer. On this car, 03 CL-S and the last, an 02 RSX-s, I was told by the dealer VERY FIRMLY not to change the oil for 5,000 0n the RSX and 3,750 on the CL. But let's get more scientific about this.

First, aluminum has a higher "specific heat" than cast iron. What that means is that if a given btu load (british thermal unit, the amount of energy required to raise one pound of water one degree f) is given to both a cast iron and aluminum block of the same size, the aluminum block will heat up faster. If cooled, aluminum will cool down quicker than steel also.

What they don't tell you, is that an aluminum block at 400 f will loose 50% of its' tensile strength, where as cast iron will lose only about 10 %. Read tensile strenght as the "ability to resist tortion", or twisting. I know, we don't run anywhere near 400 f, but if you fly airplanes, where steel is used only when absolutely necessary (because it can influence the compass), this is nice to know.

What we SHOULD be doing is ignoring the miles, but pay attention to the TIME the oil is used. In airplanes, we change the oil every 50 hours. Intrestingly enough, at 60 miles per hour (in a car), gee... that works out to...3,000 miles! And interstingly enough again, a 150 mph airplane will cover 7,500 miles between oil and filter changes.

I like what my dealer does to people who ignore oil and filter changes. They fax them the cost to install a new engine and remove the old one.

Something has changed here, and I don't know what it is. At 3,000 mile intervals, my 97 Type R oil was pitch black when changed. I saw the oil come out of the RSX at 5,000 mile intervals, and all it did was change from the original color of oil to something resembeling your average maple syrup-and you could still see through it!

What ever. Two final points. Oil changes on the RSX were about $24, now with the CL, suddenly it is $37. It goes without saying that a filter is new at every change. Gouging?

And crediting my former flight instructor (a United 747 chief check pilot), who made me a flight instructor, here is the best definition of an engine I have ever heard:

"An engine is a assembly of rotating and reciprocating parts, hell bent on destroying itself, but prevented from doing so only because of a thin film of oil seperating these parts." BET ON IT!

And no, I don't fly 747s. Just your basic light singles and twins. Highest speed achieved: 250 knots (288 miles per hour. Cessna 421. 700 horsepower, two 6 cylinder engines.)

 

i like the comparison between the intervals on the plane to a car.

but also keep in mind that when the engine on a plane dies, you crash. And also keep in mind that a planes engine does not potentially go through the rigors of a car engine to go by time instead of miles.

for example, grandma drives 100 miles and takes 2 hours. speed_racer drives the same 100 miles but takes 1.5 hours, and does a lot of tail gating and speeding up and slowing down and fighting traffic.

I'm hoping that a plane is more or less like grandma, not speeding up and slowing down too often and usually cruising the majority of it's miles.

Now should grandma change her oil more often than speed_racer because her engine has put in more time?

I guess the point is it depends on driving style. I virtually ignore the time interval on my car because in the last 3 years of owning it, I put in 27k miles, even though I have not driven it for the past 8 months. Most of my miles are highway cruising (PA to TX, PA to MD, PA to NJ, and soon PA to FL) and I use synthetic. I change between 5000-7500 and sometimes sooner depending on what is convenient because I travel so much, and I still check my oil every other gas fill-up and it still looks new at 7000 miles. I have not changed since I was in TX last year at 24k miles, but now at 27-28k miles, I may get the 30k service done before going to FL.

It's all a matter of convenience, but as long as you stay well within the maximum (normal driving: 7.5k for dyno, 10k for synth) I think you should be ok.

 

Ah let's see. In going back to my hot rods days, I think it was bad to mix cast iron with aluminum in producing engines because each has it's own expansion and contraction differences. For instance, this created some havic with engines that had a cast iron block and aluminum heads. This was done because they wanted to save weight and keep the engine cooler. But the system often had problems because of heat and tolerance differences. Now, it's mostly all aluminum or all cast iron. Although, I think there aren't many cast iron engines produced any longer because of the weight factor affecting gas mileage. A bi-product of aluminum engines is that it is lighter and does run cooler than cast iron. I guess I went off on a tangent...sorry!

 

Yup...

A gas power propeller (prop) engine will pretty much maintain relatively steady revs during cruising. An airplane with variable pitch/constant speed prop” will basically just change the load, but not RPMs. The rev range is that is normally seen is MUCH smaller than what is seen in a CLS.

The time/duration should not be ignored. People forget that the oil gets condensate in it and if it does a lot of "short haul" (AKA grocery runs) without a nice warm-up, it probably wants to be changed at 6-month intervals REGARDLESS of mileage.

The other part of the "grandma" equation is: extended break-in interval (engine runs at 1K to 2.5K all the time) vs. hot rodding with the engine running between 2.5K and 7K. The wear on the rings and bearings is accelerated and is MUCH higher at high RPMs (it's not a linear relationship).

 

Mrdeeno: No, when an aircraft engine quits YOU DO NOT CRASH! Not if you know what you are doing, that is. I am living proof. Three forced landings, all over heavily populated suburban Chicago. These relate to my aerial banner towing days when I was a fresh commercial pilot.

Remember, aircraft engines are air cooled, and that banner, with a parachute at the end creates a lot of drag. We used Cessna 150s that came with a 100 or 110 hp engine. We got rid of the engine and put in 180 hp engines, and lost the cruise props for seaplane props. The seaplane prop gave better low speed performance. The 180 hp engine should have made for a good 150 mph airplane with a cruise prop. We were lucky to get 70 mph with a banner attached, at full or near full throttle.

Naturally, this made cooling suffer. One forced landing was due to an overheated ignition harness while towing a White Sox game. I declared the "E" word (emergency) giving me priority over all other flying aircraft, and made it into meigs near lake michigan.

Two was a broken valve rocker arm, and I made it back to base with greatly reduced power.

Three was a full blown cylinder and piston leaving the aircraft. Incredibly, I was over a large controlled field and made the field but missed the runway. That's OK.

And that is when I decided to quit flying banners. Been flying for 35 years now, and not one engine failure when using a normal airplane for a normal use. The first forced landing is the toughest one. Aircraft engines are so reliable, that when one quits, there is a 4 to 12 second reaction time where you just don't believe it happened. Then you get busy, very busy. After surviving forced landing #1, the rest are, shall we say, comparatively easy. In single engine ships, when the engine quits, your decision is made for you. You ARE going to land. And at 5,000 feet above the surface, you have about 64 SQUARE MILES to find a spot to put the thing. Not hard.

Twins are a different matter. When one engine quits, what do you do. Continue, or land? Me? I'm landing at the next possible, practical airport. It is often said of twin engine flying, that "when one engine quits, the purpose of the other engine is to deliver you to the scene of the crash". Very true, if you do not religously practice single engine procedures. Twins, contrary to popular belief, are not twice as powerful as singles. Remember, you are carrying another engine, at least twice the fuel and probably more people as well. When one of the two engines quit, the thing will barely fly if it quits right after takeoff, and may enter a controlled descent you can do nothing about because you are at maximum weight, or nearly so.

Before I scare the shit out of someone, transport category (all airline planes) are required to climb at maximum weight on only one engine (in the case of a twin). And if the truth be known, if you had to drive as safely aw we fly planes, I guarantee you that 99% of you would not be able to drive a car.

Something I missed in the original question, does aluminum "handle heat" better than cast iron? It doesn't matter. Either engine will operate at the same temperature regulated by the thermostat. It is just you will be warmer sooner with an aluminum engine when it is cold, and the cast iron block will remain warmer, longer when shut off.

And for those of you with turbochargers on your CL, here is a tip: The last 5 minutes you drive your car should be gentle and with greatly reduced throttle so the turbo can cool down. With the FAA on the final test, if you enter the landing pattern, reduce power, and then have to increase it again, Bingo! automatic pink slip, you lose. Notice heliocopters some time after landing. They idle for a full 5 minutes, turbo or non turbo. This is so the size of the parts can "equalize".

Now, I wonder what that nuckle head did to that Cessna 421, twin that crashed into the Gulf of Mexico yesterday. The report was that he had "mechanical problems." Bullshit! Each engine has two entirely independent ignition systems per engine for a total of four. Engines do not run for three reasons. No spark. No air. No gas. (simply stated) He ran out of gas! (unless his flight controls jammed, very unlikely.)

 

dfreder370:

At least some of the planes you're flying have a reasonable glideratio; some inherent stability and you weren't over the Rockies!

Dump an engine on a flying brick or one with fly-by-wire to keeping flying, and it's ripcord time... But, that's another class of plane, etc...

 

Eric: Probably the worst, brain dead thing you could do, Would be to file and fly IFR, at night, over the Rockies, in real IFR conditions, single engine, reciprocating engine. Stupid.

 

AS above: Like some “professionals” flying into Mammoth Lakes as described (IFR & new moon, etc).