? Read here a lot that a 4.7 that has overheated is as good as toast because aluminum heads .
How is the hemi different ?

 

Most newer engines have aluminum heads. Chevy has been using them for several years as well as Nissan and others. Overheating can cause the heads to warp.

 

The hemi just has stronger heads that don't crack as easily when overheated. I've pegged my heat gauge a time or two when I'm stuck and my hemi hasn't shown any issues from it.

If you're looking into buying a truck now, I'd highly recommend the hemi over a 4.7, the mileage is nearly identical in the real world, and the hemi is a tougher engine. 03's have an issue with valve springs breaking, but it's not a big job to swap out those springs.

 

The Hemi doesn't seem to be nearly as susceptible to overheat damage as the 4.7. As for the reason, I've never seen the reason in print but I know that it's often talked about among mechanics that the 4.7 was engineered with the internal coolant channels to close to surfaces. It's often found that these seems split from scalling coolant...

 

Keep in mind that the 4.7l only requires regular gas where the 5.7l requires 91+.

Though the MPG of the 4.7 is only 1 MPG better in city/highway, its much cheaper per mile.

Right here in Mass we are seeing prices for regular at 3.69 regular and 3.99 for premium.

Just for the sake of a comparo, lets say they are both getting 15mpg. The 4.7 costs 25 cents a mile, where the 5.7 costs 27 cents a mile. This doesn't sound like much but if you average 12,000 miles a year, thats an extra $25 a month in gas. If you expect to tow higher than the 4.7l limits and need the ease of the mind around the overheating, then go for the 5.7.

For me, I use my 4.7 as a DD and tow very rarely with it so I didn't find a need for the 5.7.

Just my $.02

 

The Hemi requires 91+ octane? That would be INCORRECT. Right from the book:

"87 octane fuel is ok, but to obtain maximum performance 89 octane is recommended. There is no benefit to using fuel with an octane higher then 89".

Now I'm on record many times in denouncing the use of 87 octane in the Hemi UNLESS YOU HAVE A TUNER THAT DETUNES THE ENGINE TO DO SO. But there is no need whatsoever to use anything above 89 octane unless you have an aftermarket tuner that dictates you should do so...

 

My brother has towed his 23' camp trailer from Sacramento to the top of the Sierra's every year, twice a year, since he bought it new in 03. I asked him about how it's been running just last week and he said hasn't had any issues at 83k miles. Like every issue with Rams, I believe maintenance, or the lack thereof, is 99.9% of the problem. Between my brother and me, we have a 98,01 and 03 Ram-2-318's and one 4.7L and 160k+155k+83k=398k miles and neither one of us had a major repair or breakdown. So I am becoming more convinced it is the operators rather than the equipment.

 

[QUOTE=BWhelan;2751107]Keep in mind that the 4.7l only requires regular gas where the 5.7l requires 91+.



Who told you that? The salesman who sold you the 4.7 semi hemi?

 

p.s His 03 is a 4.7L.

 

I stand corrected. I must have been confused by the recommended 89 Octane vs the 87 in the 4.7l.

Thanks for clarifying.