two Hp ratings???
 

Why do engines have two Hp ratings????? Like a 430/475 for example.

I do believe that is no cruise/ cruise control on settings.

They hook up the computer and can choose between 430 ort 475 HP. All it does is feed more fuel to the injectors, plain and simple.

Your choice. My mech says turn it up and don't use it, but have it if you need it. Other say you'll get better mpg leaving it down. I hope some dis cuss this here.

I turn my 475 up to 550 and no significant change in mpg,but defintely increase in power :lol:

If your set for 475 then with the cruise control on and hitting a hill you'll probably get 4.0 mpg. If your set for 550 then you'll get 3.0 mpg.

I have a computer in my truck that measures mpg and this was the first thing I noticed. More fuel = lower mpg. If you use the cruise you can't control it. The cruise will put the pedal to the metal.

Right that's 430 on the pedal and 475 on cruise but why do they do that? I understand you need max HP on cruise so you can pull the hills without shifting, but why not 475/475? I don't get it.

It could be the mega fleets, were getting tired of tore up drivetrains from inexperienced drivers. They may have complained enough that the engine maker came up with a solution.

That's my educated guess anyhow. :?

It's only 430 on the pedal if you don't push it down all the way. If you do then it's 475 and more fuel.

Same as a car with a 4 barrel. Put a 6 pack on it and you have more horsepower and less fuel economy if you use it. Don't push the pedal to the floor and you can have the same fuel and performance as the 4 barrel.

Your basically installing a larger hose with a valve. Don't turn the valve on all the way and nothing will change but a cruise control will always turn the valve on full.

That's because the CC is "smarter", than the average driver, and would use only what nessesarely! :wink:
CAT's btw, use a "soft mode" which gives it 2-3mph , from a "set" speed.
For example, if i set my cruise on 65mph, it will only come to a full throttle at about 62mph...

Yeah detroits have similar settings.

It's simple, a smaller HP engine is easier to shift at low speeds. Anyone remember the old big HP mechanicals? They were a bitch to shift.

You don't want the engine to rev 1000 rpms with a slight touch of the throttle, you want lots of feel. That's what a low HP rating gets you.

Actually on CAT's there is two adjustments you can make to the cruise. You can set the window for the desired speed and you can set the cruise to hard or soft which means on the soft setting it doesn't give it as much fuel to get back up to the desired speed.Thereby saving you money. You can set the window bigger meaning the truck has to slow down more before the criuse will accelerate it back up to speed. That also means when you go down a hill the truck will attain a higher speed before the jake will come on to slow the truck down. I think the main reason they have the split ratings is to save some wear and tear on the drivelines when in the lower gears. Especially in company trucks that might have the cheaper trans/u-joints/rear ends and drivers that think the pedal must hit the floor in every gear LOL

Yes, i know, just didn't want to be specific... :D

You can't change anything on a Volvo, just speed limits on foot and cruise, and cruise increase increments.

My engine always comes on 100% even if I'm 1 mph slower. I always use the pedal to get up to speed, never resume.

Hmm. Maybe it's my imagination, but I swear that's not the case in at least one of our trucks. This one in particular is an 1998 M11 that according to the seller, was "turned up to 410". Well we all considered that a big joke, but the other day I used the cruise (I never do) and it seems to have way, way more power in cruise than when my foot is to the floor. Alot more power. I was a mild 66,000 gross and was pulling hills in high gear on cruise that normally would have me dropping two gears and 10-15 mph.

Now I'm thinking it may be 410 on cruise.

The drivetrain longevity thing makes sense.

oops

what.....was it something i said?

Wrong! A 430/475 is 430 on the pedal, 475 on cruise. The computer controls this. Most companies that have this option are thinking a driver will use the cruise more seeing as the engine won't loose as much on a hill.

All engine makes?

Yes, that is what they all do with a dual HP rating.

Some engines also have a multi-torque feature, more power in the last 2 gears.

So of course a 430/475 not "turned up" is 430 on the pedal and 430 on the cruise. And big carriers don't turn them up in order to save fuel, I would suppose. I mean that is what they are about, - why they exist?