|I would like to know how the two forms of monitoring an engines usage differ from one another and how would buying a used boat with 1800 hours compare to a cars mileage |
|I have around 400 hrs on my boat, but, my perfect pass says a bit over 2000 miles. I ride the delta, so , I do not turn off the engine as much as a lake.|
|If you consider just cruising speeds/rpm which are easier on the boat's engine than lugging along at 22 mph with ballast: |
Assume 2400-3200 RPM = 60 mph, then 1800x60= 108,000 miles.
On the other hand you have a Jeep, only used off-road or on a farm, with high rpms, high hours and low miles. Probably a better comparison.
|I've always been told that each hour on a boat is roughly equivalent to 9 miles in a vehicle. Apparently that takes into account boat's constant higher RPMs, and the constant drag in the water. |
|9 miles to every hours? that seems a little low. I woudln't think a boat w/ 1200 hours is equivalent to a car with 10,800 miles. Am I doing something wrong? typo? Hours can be very decieving, someone once posted its better to look at the boat and the condition its in. off course there are exceptions.|
|At the current rate of exchange 9 miles (CAN) would equal 90 miles (US).|
|hours can be misleading and there are different levels of care people give their boats. since you don't really know how the boat was used and cared for, you could look at what you could expect out of the engine. around 2000 hours is what i usually hear for the life expectancy of an inboard engine before needing major repairs or overhauling. |
neither miles or hours will tell you how hard the engine was run. the condition of the interior and hull shoud give you an idea of the care the engine received. if the rest hasn't been taken care of, the engine probably hasn't either.
|I have like 280 hrs on my boat and I bet more than half of the hrs are at idle. So It depends on what the person your buying it from did with it. I.E buying a boat from a ski school with 200 Hrs's you can bet it was under a load 99% of the time. |
|I'm convinced there's a magic formula out there that needs to be written by some wanna-be PhD (not me). It involves at least these factors, and intends on guesstimating the amount of engine life used and remaining, and not just in boats: |
1) engine hours
2) total number of engine revolutions
3) gallons of fuel burnt
4) miles (far more important for overall drivetrain than engine)
5) the final one is a list of items that can can hurt an engine, and I'm not sure how you factor them in, but: age, time spent above 75% of redline, longest oil change interval, occurrences of overheating, longest period of non-operation, average interval between uses.
For absolutely sure, there's way more to the decision than just engine hours (or odometer in a car). Each engine/platform combination (4.0L in GS400, 4.0L in Epic, 5.7L in Tahoe, 5.7L in Eliminator, 5.7L in 40' house boat, 5.7L in Wakesetter, 5.7L in Camaro) would have a different baseline in terms of fuel efficiency and some other items.
If I had my choice between just hours/miles or gallons of fuel burnt, I'd choose the latter (assuming I had access to the same REALLY general numbers of engine life in terms of gallons burnt like we have with car miles [200K] and boat hours ).
Hard driving (loading, acceleration, rpm, etc.) has MAJOR impact on engine wear & life but has ZERO impact on hours or miles. However, fuel burn measures a combination of quantity and quality of miles/hours (hard driving burns more fuel, increases wear for a given mile or hour).
Hauling ass to the river with a boat behind you will burn the same amount of fuel as driving 55 nearly twice the distance. Which encountered more wear? Although neither's perfect, in this example which is a better judge of the wear on the truck, miles or gallons?
I look at that magic formula kinda like the Blue Book calculator (miles, years, condition, options, 'oh it's silver, subtract $300', etc.) It'd make a good thesis topic I think.
And also agree with Adam - a beat up interior is a red flag. Would focus that a little more by adding a visual inspection of the engine. Is there stuff that should've been addressed? Leaks, bad hoses, etc. Is there evidence that whoever worked on the boat was a hack (bailing wire, plier teeth marks on bolts, etc.)
|I was told that a good formula to use is; |
50 hrs on a boat year is equal to 15,000 miles a year on a car. The fomula sounded good to me.
|Uh...best formula I have is my perfect pass. Maybe you can double the miles for double the RPMs or something. Aren't marine engines balanced and blue printed? That means they would be in better shape than a car engine as far as wear if it is true. Even though it sounds good to get a 4 year old boat with 150 hrs on it, having an engine sitting around for months and months at a time is worse than it being used in my opinion.|
|I agree, If I had the choice of buying a boat with 50 hours on it it vs 250 hours I'd take the 250 hour one if it was kept in good condtion with regular oil changes. |
Rany 50 hours on a boat =15000 miles seems really high. WAY to high.
Even if you looked at it really simple. On the highway you do 60 miles per hour.
even if you doubled it to 120 miles per hour, your engine RPMS would be much higher than what you run your boat at. That would equate to 6000 miles per 50 hours.
You're not always running flat out, we spend a ton of time at idle or trolling. I would say 4-5000 miles per 50 hours tops.
|I agree Pat. On a new baot your still working out minor problems @ 50 hours. Theboat is hardley broken in.|
|sorry everyone, I was mistaken. The rate I was told was 1 hour = 90 miles, not 9. You're right Curtis, 9 miles would be way too low. |
|PerfectPass shows miles? Is that some conversion, or does it display actual miles? What readout? |
|I have perfect pass digital pro. You have to go through the menus. You have to hit the two button's on the right at the same time. I takes you through through the settings, water temp, miles, hrs and things. It is directly off the paddle wheel. You get your speed from it, so the next in line is the miles.|
|Wow, I had no idea. I'm gonna have to check that out. Thanks.|
|Swass, You are such a "hillbilly" |
|lol. Dude, I'm clueless!|
|Boats are always at high rpms so I have been told that it can be estimated that 1000 hours is similar to a car with 100,000 miles, and 3000 hours is when the motor gets pretty beat. Actual miles will vary, but when you compare rpms of a boat to a car, you can see the boat will be running much higher. Even cars very though. For example, I work at a marina and the truck has around 1000 miles and 80 hours because around the shop it is always going slow, where as my personal car has 2900 miles and 62 hours. Aside from engine wear you have to think that boats have more time with people anchored, etc and thus the interiors wear faster because they have many more hours than the hour meeter alone says.|
|I've always gone with 1000 hours equals 100,000 miles. But personally I look at the condition of the boat and sound of the engine more than what the hour clock says. |
Is damn easy to disconnect the hour clock or fit a new one.
Mileage or hours do not take in consideration the maintenance or how they were clocked up.
Depending on how/where you ride you may clock up 30-40% of your hours at tick over and I'd rather have a boat with 1000 hours that has had its oil/filters changed regually than one with 500 hours and only a few changes.
I change my oil every 100 hours and cover on average 150 hours per year, a lot of which will be at tick over or very low speeds of say 8mph or less as I have speed limits to get to my ski area. If it was all constant high rpm/load then I'd changed every 50 hours.
|It is recomended that a cars oil be changed at 3000 miles? A boat at 50hrs. So in my book, 50hrs=3000 miles |
so, 1000hrs=60K miles.
The magical 100K in a car would be about 1650hrs on a boat.
Thats what I think anyway.
|Ford recently switched to a 6,000 interval, I think.|
|I keep seeing everyone saying their wakeboard boat runs at high RPMs. What is high? Mine runs around 2800 RPM towing a wakeboarding at right around 23 mph. My car runs at around 2200 RPM doing 75 mph (with overdrive on). At top speed, my RPMs are somewhere around 4500 RPM so I typically am running at around 65% of WOT. Is that high? What are you seeing on your boats? |
(Message edited by wakeshoe on October 29, 2004)
|My truck has 1721.4 hrs. on it at 50601 miles|