Hi there,

I've been reading this list for a few weeks, but this is my first post. Has anybody planned how they intend to run in / break in their new cars?

I found an interesting site that advocates running in hard, the crux of this seems to be that when the engine is loaded, this puts pressure on the piston rings, and forces them into the crosshatch pattern on the cylinder wall, helping them to form proper seal for the rest of the life of the engine. Apparently there is a window of opportunity of about 20 miles before the cross hatch pattern is worn away, whether you drive hard or easy.

http://www.mototuneusa.com/break_in_secrets.htm

Food for thought.

Pat Felstead
Melbourne Australia - We get the new Z next year

 

There are a couple of techniques that are similar to what I have understood as safe or proper break-in. The first is varying speed / RPM. The second is no full throttle bursts. If you notice he says 40-60, 40-80, and 30-100% throttle runs. What surprises me is the statement about the first 20 miles. The fact of the matter is most new cars coming off the truck will have between 5-10 miles on them already. Even though we tell our dealers not to drive, I will find it hard to believe most of us will get cars with less than 15 or 20 miles on them. Maybe cars need more miles because they don’t have as high of a redline and may need more use for break-in. I do know I will do the above, but I will not beat on the car. We all know how hard it will be to stay calm and refrain from dead stop acceleration tests for the first 1000 miles. Thanks for the article, it has helped me decide how to approach the break-in period.

 

Very interesting article. I also thought his point about changing the oil at 20 miles was interesting. Now my question is (I don't know much about breaking in cars): Does this guy know what he's talking about ...or IS HE FULL OF CRAP???

 

I think there is some truth to his article, but I will probably only do the things that is common between the factory recommendations and his procedure. (Best of both worlds!) The break-in period as described in the G35 manual does not say you have to "Drive Miss Daisy" but it does say don't floor it and beat the living crap out of it.

 

I didn't read the article, but I wouldnt be pushing it in the first 20 miles. It is good to get some full throttle acceleration on the car in the first 1000 miles to seat the rings though. The cross hatch won't wear off in 20 miles, when I tore down my '70 455 for my Buick it has 120,000 miles on it and still had some factory cross-hatch left. What I am doing is driving it easy for the first 100 miles or so, change out the break in oil to a good quality conventional. Then I will start getting on it, some full throttle acceleration, but not in first gear and not to redline. Then at 500 miles I will change the oil again with conventional, and run it up to redline a few times at full throttle. At 1000 miles I will put in Mobil 1 and from that point on run it as hard as I want.

 

His entire premise is based on the statement "The rough crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly "use up" the roughness, regardless of how hard the engine is run. "

I have no idea if that is even true.

 

I don't really think these days there is a break in period for new cars. With computers the tolerances are so close that break in periods are no longer necessay. Went i purchased my 1990 3000GT in 1998 there was no information in the manual on breaking in the car. The salesman who went over the car with me before I took it home mentioned nothing about a break in period. I drove it as I normally would and it now has 72,000 miles and runs perfect. I have had no work done on the engine except for tune-ups and oil changes.

 

That may be true, but what the "salesperson" says is worthless.

 

Is the break-in for variable valve timing engines different than normal engines? I know that the S2000 break-in specified that the engine not be rev'ed into the VTEC range before a certain mileage. I believe this is the case as well for the IS300.

Just wondering.

JD

 

I read the article that was referred to and I point out it was for motorcycles. I had a craving a couple of years ago for a bike, so I subscribed to Cycle World and a couple of other mags. Their breakin was much more crucial than cars. I read that no synthetic oil should be used until the bike was fully broken in. I have not read any thing resembling that about cars. What about corvettes and bmws, they come full of Mobile 1 from the factory and vettes use 5w-30 exclusively according to Mobile's website?

When I bought my 97 Accord new, the salesman said "don't worry about breaking the engine in". I asked why? He said that Honda runs in their engines at the factory, so there isn't any breakin. I took him at his word, when I left the dealership, I ran it to redline in the first three gears. I had the oil and filter changed at 37-3800 miles, put in Castrol full synthetic and I used 3/4s of a quart of oil in 56,000 miles , keeping to the 3-4000 mile change intervals. I used the 3/4s of a quart when I left the oil and filter change until 7500 miles. I sold the car last year for 48% of what I paid for it in 1997 and was taking it to the torque peak or redline whenever I felt like it. Go figure.

I will follow Nissan's requirements and a few of my own, as I outlined elsewhere in this forum. No way am I going to follow the guy rec's in the other site.

Boomer BR/FR

 

You are correct, after I read the Honda manual, the only thing they recommended was to vary the engine speed for a set period of time. I didn't repeat my runs to redline until their mileage rec's said I could drive "normally". The devil made me do it the first time. Obviously, the car sustained no damage that time.

I might not be so lucky the next time. I've waited too long for the Z to repeat my previous actions. JDZ, thanks for being the "voice of reason".

Boomer--Properly chastised
BR/FR