underpower

[2stacksuperdog]

I think the old macks were rated at the wheels right?

[Green Dash]

Hmm, 15-20% % less at the wheels huh? I guess my last E9 truck didn't get the memo, it was rated at 440hp and made 560 at the wheels, don't know why it was so much higher .....

That's false advertising. You shoulda taken it back and demanded they fix it while it was still under warranty.

[b61mack]

I think the old macks were rated at the wheels right?

If they were not, they were under rated, or the cummins were over rated.

[farmer52]

All engines are rated at flywheel per SAE standards. This was/is true for all OEs. I do not know of any OE that advertised "wheel horsepower". Even the automobiles/pickup trucks are engine ratings and not wheel HP.

[Dirtymilkman]

Many many years ago Mack rated power at the rear wheels. They did that because they were not a vendor engine. You bought a Mack the way they engineered it and built it. That way you had that amount of power to the ground. One issue though was price, companies didn't wanna pay as much for a 237 mack when a bigger Cummins cost the same.

[2stacksuperdog]

I know one thing our little 237 use to run circles around 300 cummins. and our 350 runs circles around 425 CATs. And dont forget our trucks always were loaded 2-3 ton more because they were s

[b61mack]

Many many years ago Mack rated power at the rear wheels. They did that because they were not a vendor engine. You bought a Mack the way they engineered it and built it. That way you had that amount of power to the ground. One issue though was price, companies didn't wanna pay as much for a 237 mack when a bigger Cummins cost the same.

I bought a 72 R model from a guy that used to have Mack Trucks of Indy in the 80s dyno tune his 237, it was putting out 248 HP to the wheels when I bought it. he also asked the guy what is the most HP he seen out of a 237,he said he had one that was putting 290 to the ground not flywheel HP.

[theakerstwo]

Many many years ago Mack rated power at the rear wheels. They did that because they were not a vendor engine. You bought a Mack the way they engineered it and built it. That way you had that amount of power to the ground. One issue though was price, companies didn't wanna pay as much for a 237 mack when a bigger Cummins cost the same.

That is a truck driver myth.at least since the early 60 I know mack engines we rated at the flywheel.If you think about it a injection pump id how the HP is set and if the HP was set at the wheels the pump rebuilders would have to set the pumps on the engine when being dnynoed.I have hrard this all of my working days and it started on the road over the CB.

[rsb502]

Mack is rated at the Flywheel just like all the rest but I still think the old Macks were underrated by about 10%. I was told by the Maintenance Manager at Howard Baer that when they got their old R models with the 300plus in them they had to take one back for something and they had them dyno it and it made 300 at the wheels. I had another owner op here tell me he had the same thing and old 300+ that made 300 to the ground without touching a thing and would out pull a 350 Cummins up MtEagle any day of the week, he knows his trucks too, had a KT600 in a Freightliner and a 3408 Cat in a KW W900A model. Old Greasy told me he bought the R model 300+ Mack because it was on the lot and he was trying to piss off the KW dealer that said he couldn't sell him a truck he wanted ay cheaper, so he went and bought one just to prove he would, after they used it they loved it so they kept it for years after.