4.8l...whats The Point?

Erik F · January 28, 2008

I was just wondering...what is the point of the 4.8l motor? Its make up is very similar to the 5.3. I have no reason to think it would cost that much less to make than the 5.3...and power output is very similar to the 5.3 (295hp/305tq vs 315hp/335tq). It would just seem smart to put 5.3's in everything...unless there is something I don't know about the 4.8l. I have an 08' Silverado with the 4.8L in it...I guess I just don't understand why they even make it...its smooth enough and has good power...but why did they make it?

y2kz71 · January 29, 2008

so you think the longer stroke gives you 30ft/lbs of TQ?

Erik F · January 30, 2008

so you think the longer stroke gives you 30ft/lbs of TQ?

Yes...you're talking about another .5 liter of displacement.

y2kz71 · January 29, 2008

I have the 4.8 in my truck also...but the question still remains...what is the purpose of the 4.8...I really don't see how its that much more costly to build than the 5.3...they both use the same block and computer...same bore and head...the AFM parts are prob cheap in comparison to the parts the are common to both...is it purely marketing? Does anyone know the thought process GM was using when putting 2 engines so similar out there?

The 5.3L for the GMT900 got the 6.0L heads and a larger 87mm throttle body...they arent the same.

Erik F · January 29, 2008

http://media.gm.com/servlet/GatewayServlet...amp;docid=21579

The Vortec 6.0L and 6.2L engines offer a significant power level increase compared with previous premium engines, with much of the newfound power coming from high-flow aluminum cylinder heads. The heads are based on the racing-derived cylinder heads of the Corvette Z06’s LS7 7.0L engine, including a unique inlet port shape and offset rocker arm design. Airflow of the heads is supported by large 55-mm-diameter intake valves and 40.4-mm-diamter exhaust valves. “The heads use the high-performance technology of the Corvette’s LS7 to build efficient power in truck engines,” said Meagher.

Vortec 4.8L and 5.3L engines also have high-flow, Corvette-derived heads. They are based on the previous-generation Corvette Z06’s LS6 engine’s cylinder heads and have flow characteristics commensurate with the engines’ airflow-to-displacement needs. All the Gen IV Vortec engine variants use the same efficient ignition coil packs of the LS2 to light off the air/fuel mixtures that are drawn through the heads.

y2kz71 · January 29, 2008

The GMT900 5.3's get the 243 heads from the 6.0's and the 6.0's get the new L92 heads. Im not sure if the 4.8's have the EXACT same head...theres gotta be some reason the 5.3's have alot more hp and tq

y2kz71 · January 29, 2008

The initial cost of the truck. Trucks with the 5.3 cost significantly more than trucks with the 4.8. I think someone (might have been here) said that their monthly payment would be $60 a month higher with the 5.3 than with the 4.8. That works out to be an extra $720 every year.

Was he financing it for 10 months...its only a $600 option

Erik F · January 29, 2008

The 4.8 and 5.3 have the same bore...but the 5.3 has a longer stroke

Erik F · January 29, 2008

I have the 4.8 in my truck also...but the question still remains...what is the purpose of the 4.8...I really don't see how its that much more costly to build than the 5.3...they both use the same block and computer...same bore and head...the AFM parts are prob cheap in comparison to the parts the are common to both...is it purely marketing? Does anyone know the thought process GM was using when putting 2 engines so similar out there?

2000DV4.8 · January 28, 2008

I was just wondering...what is the point of the 4.8l motor? Its make up is very similar to the 5.3. I have no reason to think it would cost that much less to make than the 5.3...and power output is very similar to the 5.3 (295hp/305tq vs 315hp/335tq). It would just seem smart to put 5.3's in everything...unless there is something I don't know about the 4.8l. I have an 08' Silverado with the 4.8L in it...I guess I just don't understand why they even make it...its smooth enough and has good power...but why did they make it?

The initial cost of the truck. Trucks with the 5.3 cost significantly more than trucks with the 4.8. I think someone (might have been here) said that their monthly payment would be $60 a month higher with the 5.3 than with the 4.8. That works out to be an extra $720 every year.

racedvl · January 28, 2008

Just for the sake of argument, if the 5.3 & 4.8 are mostly the same, why not have the 5.3 more affordable?

Zembonez · January 29, 2008

ACTUALLY... you bring up a very valid point. Too many options are one of the main reasons American auto manufacturers are not as efficient as Japanese manufacturers. I'm not trying to start a war here but it is a fact that they aren't... YET. We are headed in the right direction.

As of right now though... Look at any foreign manufacturer and they will offer 2 or 3 trim levels of a vehicle (with most items standard to that particular trim level). Usually there are 2 engines available... period. Additional "options" are offered but are installed by the dealer. This streamlines the build process, increases their capacity for quality control, and keeps complexity and cost down. It is one of the primary reasons most auto plants here have been completely reorganized over the last decade.

I believe the old order it however you want it method of buying a vehicle is quickly going to go away. I'm not saying I think that is good, but it is good for competition sake.

2000DV4.8 · January 28, 2008

Just for the sake of argument, if the 5.3 & 4.8 are mostly the same, why not have the 5.3 more affordable?

Well, the 5.3 has AFM (in the GMT 900 trucks), and the 4.8 doesn't, so that's a big factor in cost.

Zembonez · January 28, 2008

Just for the sake of argument, if the 5.3 & 4.8 are mostly the same, why not have the 5.3 more affordable?

Well, the 5.3 has AFM (in the GMT 900 trucks), and the 4.8 doesn't, so that's a big factor in cost.

AFM is exactly the reason I have a 4.8... plus it was cheaper to boot. I like the sound and smoothness of a small displacement V8.

Just imagine when that stuff starts to croak. It's gonna be hell.

K.Jump · January 30, 2008

The initial cost of the truck. Trucks with the 5.3 cost significantly more than trucks with the 4.8. I think someone (might have been here) said that their monthly payment would be $60 a month higher with the 5.3 than with the 4.8. That works out to be an extra $720 every year.

Was he financing it for 10 months...its only a $600 option

LOL

Norman · January 28, 2008

AFM is exactly the reason I have a 4.8... plus it was cheaper to boot. I like the sound and smoothness of a small displacement V8.

Just imagine when that stuff starts to croak. It's gonna be hell.

That's exactly why I got the 4.8 - The benefit of AFM was going to be negligible in comparison to repair costs when some of that computer wizardry hits the proverbial fan.

My 4.8 in a Regular Cab is plenty powerful, and I haven't even done exhaust, intake, or chip yet.