Whelp, we did it: My wife and I bought a broken Cayman in Seattle, Washington, and then drove it all the way home to Florida in fourth gear. Washington, Oregon, Idaho, Nevada, Utah, Colorado, Arizona, New Mexico, Texas, Louisiana, Mississippi, Alabama and Florida: As we learned, these are all states that can be driven across in a Porsche screaming at …
You know you have your own Oil Analysis guy here..... Just sayin'.
One of the longevity tests manufacturers do is to just run the engines at redline and full load for weeks on end. I think it'll be ok.
Why this oil? It was also in our care package from LN Engineering, but came well-reviewed from the oil analysis folks, too.
I mean, the founder of the lab is also the developer of the oil so I would be shocked if they were critical of it.
Bob, I didn't realize you were an oil analyst. What do you think of the results? And was I correct in going into this with the assumption that this would be no big deal, anyway?
In reply to Tom Suddard :
There report is a bit hard for me to read. Not sure why they add all the wear metals together. Kinda odd but maybe that's their thing. I do know they use a different method for their elementals. It's an older out dated method that's being bright back with new technology and equipment.
as for the results themselves the appear normal. There is always wear in an engine. It's the amount you need to watch. Keep in mind sampling procedures (how you obtained the sample) can have the largest effect on results. There's a lot of variables in play. That sample wouldn't concern me. If you were truly worried I'd continue to sample to monitor the trend to make sure it's fine. But barring any known issue I wouldn't be worried about running an engine for extended time at higher rpms.
edit: although I think maybe I should raise my prices if they are charging $70 per sample
You said it was mystery oil that you drove across country - but the initial analysis referred to Mobil 1. So does the lab believe it was Mobil 1 in the engine when you bought it and drove it across country?
bobzilla said:You know you have your own Oil Analysis guy here..... Just sayin'.
Bob is the oil guy...?
In reply to t321sg :
There's no real way for the lab to answer that question. Additives can be similar but be sold as different oils using a different base stock. The way its supposed to work is you work from the information on what the oil is supposed to be. When you start looking at the sheer volume of oils out there trying to work backwards is just not something you can do reliably nor cheaply.
j_tso said:bobzilla said:You know you have your own Oil Analysis guy here..... Just sayin'.
Bob is the oil guy...?
Not that guy, but kinda
t321sg said:You said it was mystery oil that you drove across country - but the initial analysis referred to Mobil 1. So does the lab believe it was Mobil 1 in the engine when you bought it and drove it across country?
We drained mystery oil out of the car before driving cross-country, then drove across country on the Driven DI40.
Bob's correct--there's no easy way to tell what was in the car when we purchased it. But given the dealer service history and the lab's observations, we suspect it was Mobil 1
The race engineer in me says this test proves that you should run the car closer to redline constantly. All this longer gearing stuff might save some fuel but it's KILLING your engines.
In reply to Andy Hollis :
Interesting fun fact.... the new forte with the spoolie boi runs 80mph at about 3400rpms. That's also about where it gets fantastic fuel economy, hovering around 40mpg. When I drive to work and short-shift and keep the revs low, I get 37.
Andy Hollis said:The race engineer in me says this test proves that you should run the car closer to redline constantly. All this longer gearing stuff might save some fuel but it's KILLING your engines.
I'm a firm believer in a few hard pulls to redline every time the car is driven (assuming you wait until everything is up to temp). For instance, went to grab lunch today on the way back is a long on-ramp back on to the Turnpike. 1st-4th to redline in each gear, before slowing back down to just above the speed limit as I merge.
4100 RPM? That's an normal highway cruise for a Miata driver. :)
4100 RPM? That's an normal highway cruise for a Miata driver. :)
In reply to jstecz :
Pretty sure that's where the wifes first gen manual RAV4 ran at highway speeds. The engine was fine, but the cats weren't happy after 30 hours of straight running.
This is AWESOME, Tom!
I'm eventually going to make my own P-Car purchase, so it's super cool to read about your adventure!
jstecz said:4100 RPM? That's an normal highway cruise for a Miata driver. :)
jstecz
Exactly, we have proven that a 10 year old Cayman is the equal of a 34 year old Miata.
S1 RX-8s (NC Miata platform ;) ) do around 4k at 80mph. They get better fuel economy at 55-60mph, which is probably expected for multiple reasons.
Back in '77-'80 I drove 400 miles round trip Yuma to Phoenix every other weekend, mostly at 90 MPH. In a '70 Mustang (Corvette Yellow) with a 351 Cleveland 4V, FMX automatic (no OD), and 3.00 gears, 4,000 RPM cruise was normal. Never had an engine issue.
Unless you include the one time: A fan belt came off, taking the other two with it, and the transmission fluid lines for good measure, near the Barry M. Goldwater Air Force Range south of Gila Bend. I had to leave the car on the side of I-8 and came back the next day with two friends, parts/ tools. We had just finished fixing it when a deafening explosion right above our heads sent us all to the deck. I looked up to see an F-15's tail, just 50 feet off of the deck, high-tailing (low-tailing?) it for the bombing range after "buzzing" us. Guess he saw three jar-heads standing around a yellow car and just couldn't resist. I can imagine him calling "tally-ho!" as he spotted us on his way out of Luke AFB. Bad-ass cool!
In reply to bobzilla :
Engines have their best BSFC (brake specific fuel consumption) at their torque peak. I suspect at 80 MPH you are nearer that RPM, and the turbo is probably helping out some at that point too. So long as you are below the point when boost crosses the threshold to when the computer starts retarding timing and/or enriching the mixture, the turbo can make the engine more efficient.
I'm going to posit that the following are both true: (1) you didn't ruin your engine and (2) this oil test isn't particularly meaningful by itself.
Aside from catastrophic failures that you'd notice anyway, you're not going to get much of anything from a single oil analysis. I do them on most of my cars as well as my airplane. They are useful, but not especially useful in a vacuum. The way they are useful is when you do them regularly, collect trends, and then notice unusual data that you can't correlate with a change in usage.
50 hours after I bought my airplane, I changed the oil. Here's the oil analysis:
Taken by itself it's hard to say much from it. The most value is that compared to the provided averages from the same engine, aluminum and chrome are high. You'll note that the comments on it are concerned, but not alarmist. The oil filter told a much clearer story--it was completely full of metal. We took the airplane out of service and sent off the engine for an overhaul before even getting the oil report back. On disassembly it was clear that the camshaft and tappets had ground themselves into oblivion.
This is a best-case scenario for a one-off report like this. In your case, there are no averages from similar vehicles. Worse, driving cross-country with few heat cycles over those 4,500 miles is likely completely different usage from the total unknown "baseline" of the oil that was in the car when you bought it. Maybe you did cause excessive wear and have no idea because you don't have anything to compare it to? I don't think you do, and I'd be seriously shocked if driving across the country at 4,000rpm did in that fancy engine did real damage.
Mostly I just want to caution against using single reports like this to pronounce an engine "healthy". At most you can pronounce it, "not obviously destroyed."
I once did an oil sample on a 3.0 Toyota engine and discovered large chunks of piston in it. No external lab was required to come to a conclusion. And by "oil sample", I mean "I was draining the oil and piston parts came out".
bobzilla said:In reply to Andy Hollis :
Interesting fun fact.... the new forte with the spoolie boi runs 80mph at about 3400rpms. That's also about where it gets fantastic fuel economy, hovering around 40mpg. When I drive to work and short-shift and keep the revs low, I get 37.
I put 4.78 gears in an '85 RX-7 with 205/60-13 tires and with the engine spinning 5000rpm down the highway, I was getting 32mpg.
(before you ask, yes that is after correcting the odometer. it was over "40"mpg before correction)
On the other hand, when I had my T-bird, I drove for a week without using 3rd gear because I was thinking about dropping the 2.77 gears in favor of 4.56 gears and wanted to see what it was like to drive. It was something like 4000 at highway speeds. Oddly enough a 429ci pushrod engine does NOT respond well economy-wise to spinning that fast.
(i didn't go with the 4.56s)
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