05 Vortec 4.8l V8

[Bill in Utah]

Originally Posted By: XS650
Originally Posted By: ekpolk
But if I were ordering, I see no reason I'd ever order the 4.8L. It produces substantially less hp and tq, while having worse fuel econ than the 5.3. I don't even get why the 4.8L still exists in the line if GM is unwilling to confer upon it the benefit of cylinder deactivation, etc.


It exists to make the 5.3 look good.


So how many miles have you operated a 4.8l?

(sorry, but what a statement)

The 4.8l is a excellent engine that gets great fuel MPG without all the hightech C R A P that people seem to have to have.

I had a 2008 5.3l tahoe with the cylinder deactivation that was a joke. The only time it came on was during coasting or going down a hill. The computer on the dash stated it was a 4cyl getting 40 some odd MPG.

(and the tank overall MPG was 23.9)

Funny how the MPG over a tank was only 16.1 when taking miles vs how many gallons used.

I'd take the 4.8l (and since I have OPERATED it for 7 years) over a 5.3l (which I have also OPERATED).

Esp if the 5.3l has all the high tech garbage.

Simple is better. Some times bigger is not better.

I've got many miles on both engines so I can speak from ACTUAL use.

 

[XS650]

Bill, I could have been clearer.

The 4.8 is a 4.8 instead of a 5.3 without high tech [censored] because if the base V8 were a basic 5.3 without high tech [censored] it would make the 5.3 with high tech [censored] a harder sell.

The difference in cost between producing equivalent 4.8 and 5.3 liter engines is approximately nothing, as is the difference in economy, all else being equal.

 

[Jim 5]

Originally Posted By: ekpolk
Jim:

Not questioning your plan -- you've done the homework, and I have not. I'm curious, though, at what point does it become more practical to simply do an engine swap versus trying to rebuild to the new displacement? Put another way, if you could find a good, low mileage 6.0L in a nearby yard, might it not be easier to just transplant whole engines?


That is my thought as well. I have a line on a low mileage escalade engine and transmission. Additionally, and before the engine goes in, I plan a cam change to optimize torque and headers to provide inexpensive hp/$ improvements while everything is removed. I am acquiring a spare pcm and plan to send it to a company that is well respected on the LS1 boards to optimize the "flash" for the escalade LQ9 customized to the the particular cam, header and towing oriented transmission combination I have in mind. Others who have done this swap have even seen an improvement in MPG's.

Once I have spent an evening changing the cam, I am confident I can replace the identical (externally) engine and transmission in no more than one weekend. Furthermore, for around $5k this is a far more economical option than changing vehicles (since a 6.0L avalanche didn't exist until 2007 and the difference on trade/upgrade would be at least $25-30k). Not to mention the fact that I think I could sell the extraordinarily well maintained engine (UOA's available) and trans combo for at least $2k.

It is the most cost effective solution to the problem that I have found the ideal vehicle for our family and its needs, except that it is not powerful enough to take our trailer to all the places we want to see. Plus it is a very interesting challenge to me having done similar projects on low-tech carburated vehicles.

Within 3-4 months I hope to have all of my ducks in a row and the project completed.

 

[GMBoy]

Originally Posted By: Jim 5
Originally Posted By: ekpolk
Jim:

Not questioning your plan -- you've done the homework, and I have not. I'm curious, though, at what point does it become more practical to simply do an engine swap versus trying to rebuild to the new displacement? Put another way, if you could find a good, low mileage 6.0L in a nearby yard, might it not be easier to just transplant whole engines?


That is my thought as well. I have a line on a low mileage escalade engine and transmission. Additionally, and before the engine goes in, I plan a cam change to optimize torque and headers to provide inexpensive hp/$ improvements while everything is removed. I am acquiring a spare pcm and plan to send it to a company that is well respected on the LS1 boards to optimize the "flash" for the escalade LQ9 customized to the the particular cam, header and towing oriented transmission combination I have in mind. Others who have done this swap have even seen an improvement in MPG's.

Once I have spent an evening changing the cam, I am confident I can replace the identical (externally) engine and transmission in no more than one weekend. Furthermore, for around $5k this is a far more economical option than changing vehicles (since a 6.0L avalanche didn't exist until 2007 and the difference on trade/upgrade would be at least $25-30k). Not to mention the fact that I think I could sell the extraordinarily well maintained engine (UOA's available) and trans combo for at least $2k.

It is the most cost effective solution to the problem that I have found the ideal vehicle for our family and its needs, except that it is not powerful enough to take our trailer to all the places we want to see. Plus it is a very interesting challenge to me having done similar projects on low-tech carburated vehicles.

Within 3-4 months I hope to have all of my ducks in a row and the project completed.


I was wondering what happened to you and how that project was coming along. Last time we spoke thru PM's.

 

[GMBoy]

Originally Posted By: rpn453
Originally Posted By: ekpolk
Car and Driver has an article on the Tahoe Hybrid in the latest issue (March 2008). The author states that GM used the 6.0L version of the engine for the hybrid because of torque advantage at lower rpms.


I just read that article. I was surprised to read that it's an Atkinson cycle engine, so it's not as strong as the regular 6.0L.



332HP is not exactly weak and when you accelerate with BOTH gas and hybrid power together the acceleration is rather brisk.

 

[addyguy]

As gas gets more expensive, having smaller engines will be a better thing for manufacturers to have. I see the 5.3 engine becoming less popular, and possible discontinued; and only have 4.8 litre and smaller engines for 'street' trucks, and 6.0 litre and bigger engines for work trucks, where fuel economy isn't as much of a concern.

I'm very impressed with the 4.8 - FIL has one in a Silverado LS extended cab and it goes like stink, but is very smooth and quiet. Nice truck.

 

[ekpolk]

Originally Posted By: rpn453
Originally Posted By: ekpolk
Car and Driver has an article on the Tahoe Hybrid in the latest issue (March 2008). The author states that GM used the 6.0L version of the engine for the hybrid because of torque advantage at lower rpms.


I just read that article. I was surprised to read that it's an Atkinson cycle engine, so it's not as strong as the regular 6.0L.
I'm not sure how GM is implementing this, but in the Toyota/Lex hybrids, the engines use the VVT system to make them Atkinson cycle only when it's beneficial for them to be. If you tromp on it, the computer can adjust valve timing for performance instead of max economy. Again, however, I don't know if GM's system allows the engine to work this way.

 

[ekpolk]

Originally Posted By: addyguy
As gas gets more expensive, having smaller engines will be a better thing for manufacturers to have. I see the 5.3 engine becoming less popular, and possible discontinued; and only have 4.8 litre and smaller engines for 'street' trucks, and 6.0 litre and bigger engines for work trucks, where fuel economy isn't as much of a concern.

I'm very impressed with the 4.8 - FIL has one in a Silverado LS extended cab and it goes like stink, but is very smooth and quiet. Nice truck.

What I still don't get, and I haven't seen anyone really explain, is why the smaller 4.8L doesn't seem to get better mpgs in proportion to its smaller displacement. Even before the 5.3L got the "Active Fuel Management" (cyl deactivation scheme), there wasn't much difference between the economy of the two engines.

That being the case, why not opt for a 5.3L and enjoy its higher hp and tq, both of which peak at substantially lower rpms than they do in the 4.8L?

I'm sure the 4.8L is a very nice engine from an operation standpoint (and I've only driven a couple 5.3L vehicles; never a 4.8L), but that said, logic would still seem to dictate opting for a 5.3L.

 

[Bill in Utah]

Quote:
That being the case, why not opt for a 5.3L and enjoy its higher hp and tq, both of which peak at substantially lower rpms than they do in the 4.8L?

I'm sure the 4.8L is a very nice engine from an operation standpoint (and I've only driven a couple 5.3L vehicles; never a 4.8L), but that said, logic would still seem to dictate opting for a 5.3L.


Because unlike stats or worst; EPA numbers, the 4.8l gets better MPG over the 5.3l. (and I've operated both for many miles)

I never had a problem with the inferior

performance of lack of torque or HP with my 5000lb 4x4 truck (or the other 5400 4x4 truck) with the 4.8l at 5000 feet and above. (And everyone knows that engines make tons more power the higher you go)

Loaded or not. Towing or not.

Driving the 4.8 everyday will get better MPG for 99% of the public over the 5.3.

As we know, the EPA numbers are so screwy (wonder why they have been messed around with so much and still are clueless. Like most things out of the government

) and I'd not go with those too much.

Take care, bill

PS: How many pages is this up too?

 

[ekpolk]

One other interesting twist: on configurations where the buyer can choose either (there are many where the 4.8L is not allowed), the 4.8L as an option above the 4.3L V-6 costs $945, and the 5.3L costs $1,545. Saving $600 at purchase might be a good reason to opt for the smaller engine...

 

[ekpolk]

Easy Bill -- surely you can appreciate how all this looks on paper. Accounting for your experience, I hope GM decides to confer some of the fuel economy boosting techniques (VVT, AFM, etc) on the 4.8L and not just keep them for the 5.3L. You'd think they might take the smallest engine and work it up for max FE, if for no reason other than being able to advertise, for example, a full-size P/U that could do ~22mpg hwy.

 

[Bill in Utah]

Quote:
for example, a full-size P/U that could do ~22mpg hwy


Did that with my truck. 4x4, ext cab and all the comfort stuff.

You don't need all the cyl deactivation garbage.

My Moms truck gets 20.5-21.2 (2002 same truck as my 2000 but auto)

I have a few co-workers with same truck but 5.3 and they see maybe 19mpg.

Real life looks a lot different than paper.

Bill

 

[glennc]

Bill I'm taking a wild guess that you get the mileage you do because of the way you drive. Also keep in mind your elevation there in Utah helps a little bit.

Most people don't drive for mileage and I bet not that many even know how. For them I'm sure the cyl deactivation is helpful and so would be all the other techno tricks like auto shutoff/start, hybrid power, regen braking, etc.

When you are driving for economy I think you automatically do a lot of the things that those tricks would do for you if you had them.

 

[Bill in Utah]

If people are worrying about MPGs, then instead of all this garbage cyl deactivation (which again, in the Tahoe that I drove was a joke), Hybrid that, maybe they need to operate a smaller outfit?

Heaven forbid that someone had to drive a 4 cyl around more than their v8 powered truck when alone with a lunch box.

I don't know, we put way too much trust on the tech stuff which will someday co$t you more in the end.

Todays engines/cars/trucks are already too complicated, I'm not going to go out looking for more stuff to go wrong.

That is why I liked the way chevy did the 4.8l. You can work on it, all 8 spark plugs can be changed out taking your time in 30 mins with ease. Oil changes are simple. Air filter changes are simple. Had to replace a valve cover gasket, simple hour taking your time job.

I've had to change those items on other brands and it is like the engineers TRY to make things hard just to ensure that the owner HAS to take it into a stealership for the $80 an hour "techs"

to work on it. (and charge you 3 hours to change the plugs because the "book" says so)

*if* you need room then fine, get a mini van and drive it (or anything) for MPG. If you need a truck, great. Just don't expect it to get 35 mpg (like our @$#%^&% government wants) and cost within reason.

This 35MPG CAFE B S is going to KILL the auto industry. Because the public are going to go so far into debit to afford the COST of these outfits and they are going to be in the shop more than not. Plus the lightweight materials and high tech stuff is going to raise your insurance more than you ever thought.

(I had a long talk with my insurance guy when we had our Subaru in for repair. He said that his industry will be the next to have the government "help" due to increase of costs and they are going to be passing the buck)


I am So far out of topic sorry.

Back to the original post.

4.8l engine is excellent, simple and works well. Any oil good. Follow OLM.

Done. Rant over.

Sorry. Bad Bill

 

[Jim 5]

Originally Posted By: GMBoy


I was wondering what happened to you and how that project was coming along. Last time we spoke thru PM's.


Hi GMBoy,

I'm still at the research/information gathering stage. My plan is to be finished by mid may. I may still have some questions for you as the months go by if you don't mind continuing to share your knowledge.

 

[mrsilv04]

If I had to throw out a guess, I'd say a good portion of the sales for the 4.8 is for fleets and leases.

A lot of fleet and government buyers spec that the vehicle have a V8, and it be as cheap as possible. They could care less if it is a 4.8 or a 5.3. It just needs to have 8 cylinders going up and down inside the engine. It boils down to $$$ on the bottom line, and a 4.8 is cheaper than a 5.3.

My neighbor's 4.8 Silverado is a leased vehicle. He didn't have a choice if it was a 4.8 or a 5.3. It is the vehicle that the leasing company delivered to him. It would seem to me that the leasing company would see a higher residual value on a vehicle with a 5.3, but apparently not.

 

[GMBoy]

Originally Posted By: Bill in Utah
That is why I liked the way chevy did the 4.8l. You can work on it, all 8 spark plugs can be changed out taking your time in 30 mins with ease. Oil changes are simple. Air filter changes are simple. Had to replace a valve cover gasket, simple hour taking your time job.



Good point, but the same goes for the 5.3, 6.0 and 6.2

 

[ekpolk]

Originally Posted By: GMBoy
Originally Posted By: Bill in Utah
That is why I liked the way chevy did the 4.8l. You can work on it, all 8 spark plugs can be changed out taking your time in 30 mins with ease. Oil changes are simple. Air filter changes are simple. Had to replace a valve cover gasket, simple hour taking your time job.



Good point, but the same goes for the 5.3, 6.0 and 6.2

I see what you guys are saying about maintenance ease, but I really think this goes more to the vehicle wrapped around the engine, than to the engine's own virtue. Almost any engine would be easy to work on inside the vast expanse of a full-size pickup's engine room. Conversely, many folks curse today's V-6 car engines for the difficulty of spark plug changes, particularly the rear bank of cylinders. In reality (mine anyway), this is more a function of the car that fits skin tight around the engine, than some fault of the engine.

 

[Bill in Utah]

Quote:
Almost any engine would be easy to work on inside the vast expanse of a full-size pickup's engine room.


Go look at a Ford F150 built since 1997. Then go look at a Chevy built in the same time period.

I'll change the plugs in my family's Chevys. I tell who own the fords to take it to the stealership for a $200-300 plug change.

Its that bad.

My 1990, 1994 Fords were a little hard to work on but 1997 up Ford took things to a new level.

1999 V6 Taurus I owned the back and front bank was EASY to change. I could do all of the them on a cold engine under 20 mins.

My sisters 2003 Taurus is the same. Her 1993 Dodge Caravan V6 back bank is impossible to get to .

My dads honda powered Vue is a hard one to work on. Easy to change oil and filters. Thats where it ends.

Take care, bill

 

[ekpolk]

Bill:

Certainly particular engines have their quirks, but all things being equal (I know -- they rarely are...), I think you're better off under a pickup's hood than a car's (or large SUV too, I suppose). One thing I loved about our Sequoia was how much room there was around the engine, and accessories like the PS reservoir, etc. Sure, there were some tight reaches, but very accessible, for the most part. I would much rather do anything in there, than work in the cramped confines of a car, especially one with a V-6. We drove a 1990 Sable Wagon for 10 years, and I don't recall anything being especially easy to reach on that car (except maybe adding oil...). We love our Avalon, but that 2GR V-6 is huge, and appears to fill virtually every cubic inch of the engine room. I'm not looking forward to trying to do anything on that one.