Engine Hours vs. Engine Miles
 

Ok, once and for all, I've heard many theories about applying a ratio to engine hours vs. engine miles, i.e. a marine engine w/ 400 hours is comparable to an automobile engine w/ 85,000 miles, for example. Is there a formula or comparison table?

What does everyone think?

Ricochet.

Depends on how many NO WAKE zones you go through! :D

Like paradigm shift say's... depends totally on usage. Run it easy ans 1000 hrs = 100,000 miles. Run it hard, 100 hrs = 100,000 miles. Really not a good comparison between the two.

BT :cool:

really all depends.. if a guy knows how to care for a boat or has the cash to get it done..then a good 500 hours or less motor will run for a good time.. but if the boater hits every dock on the water.. then.. get a good deal

HUH!!:( :( :(

I want some of what customrigger101 is having :D :D

BT :cool:

I don't remember the last time I had my truck engine wound up to 5000 RPMs! The Honda maybe. Most V-8s on the highway are running around 1500 RPMs. Its tough to compare marine and auto environments.

?
 

Custom Rigger:

You ok dude? BH

I saw on a show that for most cars the average speed is something like 35 to 40 mph. At 40 mph it would be 1000 hrs. of engine time for 40000 miles. Pretty simple math, but coming up with an accurate average speed is the hard part.

wow i didn't even get what i posted there.. think it had something to do with general maintains of the motor.. don't post drunk. LOL

Lets see 3000 RPM = 75 MPH in one of my BB Trucks O.D. High Range 100 Hours at that rate =7500 Miles

Just rule of thumb...when high reving gas engines, mostly in high speed boats, reach the 400+ hours range they are worn pretty badly.

High speed offshore boats, ski boats, etc.

Sure you'll always find the exception. But, remember the boat engine doesn't coast. Also, most of the cruising is done at 3000 rpm's and above.

Thanks for the input guys!!

Gearhead99, thanks for that info. I see alot of boats w/ motor hours in that range. Definitely a red flag, huh??

CustomRigger101. Actually the more beers I drank, the more I understood your posting. I just needed to be in the right state of mind.

Ricochet.

If you are afraid of the hours on a boat you should have the engine(s) surveyed. You can buy a boat with 180 hours and not have a healthy power plant if it wasn't broken in right, service timley, or flushed if it is a salt water boat.

I don't exclude a boat just because oh hours.

Try this math, I run hard on the highway at 100 mph. Maintain the car properly and run 100,000 miles. Simple division and the motor goes 1000 hrs just fine.
I have had many people mention rebuilding after only 500 hrs. possible for racing conditions when all means all, and the first one across the finish line wins.
However on a pleasure boat, you or I would never even notice the power loss. Keep up on it and change the oil regular and I can tell you they can go a bunch further. I.E GMC pick up with 180,000 miles on it, Yamaha outboard with 1,800 hours on it, Honda 929 with 29,000 miles on it. Thay keep going and going so long as you keep up with the maintanance.;)

dont know an eqaition for it,but in doing a ton of insurance work,the insurance companies consider 100 hrs=to 10 thousand miles,and prorate from there...........