Nbs Vmax 6.0 Vs 5.3

Ranger · October 3, 2007

I'm in the market for a new 1500 Silverado (hopefully. I'm dealing with a lot of "negative equity" but my sales guy is pulling some strings to get it down) and I've test drove both the VortecMax and a few LTZ 5.3s. It seems like the "active fuel management" is a lot more noticeable with the Vmax, sort of a dead spot in acceleration as it switches. The 5.3 didn't have a lot of off-the-line punch but it was a lot smoother, I could barely notice the mode change without seeing it on the dash. The brakes were also a lot more touchy on the VortecMax. Is that normal or is it just a particular rare quirk?

So any personal opinions about what would be the better option overall? I do pull quite a few trailers, and occasionally I will haul up to 1,500-2,000 lbs in the bed. It will probably be a 4x4 as well, one I'm looking at is an 08 LTZ Z71.

99silverado1500 · October 3, 2007

Depends how much you tow. If you tow a lot (more then once or twice a week, for the whole year) then the 6.0 will be perfectly fine. If you just ocassionally tow here and there, the 5.3 will be the truck for you.

MS3DALE · October 3, 2007

Well for me the 6-liter was the only way to go,I always get the biggest engine available.

I haven't driven any GMT900 trucks with the 5.3 so I can't compare them to my "VMAX"

I do know that unless I look at the DIC I cannot tell if its in V4 or V8 mode.

The brakes are touchy on mine as well,But I like'em like that,Anythings better then the ones on my '04,They were spungey unlike the ones on my '99 that were also a little touchy,Also remember that the VMAX's have rear discs instead of drums.

Also with the "L76" 6-liter option you get an engine oil cooler,the M70 "Super-Duty" transmission,and the 9-1/2" rear-end.

When I ordered my truck back in January there was no question in my mind what I was getting.....It was the 6-liter or nothing!

Doomsday · October 3, 2007

I have the 6.0 liter as well, I don't tow much but when it comes to me and truck, you have to get the big motor.

A few things I noticed, I drove both trucks before buying mine, and both were 4x4 Ext Cab Reg Bed but the main difference is stabiltrac. GM trucks equipped with this feature have 4 wheel disc brakes, which I have to say should be standard by now for their trucks but its not for some reason. The 5.3 I drove with 4 wheel discs stopped on a dime, nearly tossed you out of the seat, the non stabilitrac model with rear drums, stopped the way most of us truck guys are used too, not bad by any means, but much more suddle.

Also AFM should never turn on under acceleration unless your already going 62 and want to very very gradually move up to 65, or something like that. Even in those situation I never notice the truck shifting into 4 cyl mode.

cchupek · October 3, 2007

Go with the 6.0 if you plan on towing like you stated. I have not driven the NBS 5.3's, but trying to tow a 21' bass boat with my old 2000 w/5.3 and now with the 6.0 is like night and day. you don't get near the strain on the driveline, in fact, you really don't notice it being under any load at all. Spend the extra $$, you'll appreciate it in the long run.

VMax2007 · October 3, 2007

I'm in the market for a new 1500 Silverado (hopefully. I'm dealing with a lot of "negative equity" but my sales guy is pulling some strings to get it down) and I've test drove both the VortecMax and a few LTZ 5.3s. It seems like the "active fuel management" is a lot more noticeable with the Vmax, sort of a dead spot in acceleration as it switches. The 5.3 didn't have a lot of off-the-line punch but it was a lot smoother, I could barely notice the mode change without seeing it on the dash. The brakes were also a lot more touchy on the VortecMax. Is that normal or is it just a particular rare quirk?

So any personal opinions about what would be the better option overall? I do pull quite a few trailers, and occasionally I will haul up to 1,500-2,000 lbs in the bed. It will probably be a 4x4 as well, one I'm looking at is an 08 LTZ Z71.

What you are feeling is not AFM switching. The 6.0's have more TM/Abuse mode in the ECM, therefore it lags a bit more under initial acceleration. A tune takes care of some of that.

As for the brakes, if it's a crewcab 6.0 (stabilitrak is std on crewcabs) or an ext cab with Stabilitrak, then you will get 4 wheel disc brakes. 5.3's have rear drums and 6.0's without Stabilitrak also have rear drums.

For me it was a no-brainer. Bigger, better engine: 6.0 has VVT, 5.3 does not, 6 bolt main bearings, deep skirt block, etc. HD 4L70E tranny with ext cooling, ext engine oil cooling, HD 9.5" rear end and 4 wheel dsic brakes. Which do you think will hold up better? Go for the 6.0, no-brainer. Mileage is only slightly less, if any. VVT does much more for mileage than AFM does. The 6.0 has both.

Gozer · October 3, 2007

I went with the 6.0L and max trailer package (4.10 gears) since I tow a 27' travel trailer in PA mountains a few times a month in the camping season. If I wasn't towing that, I probably would have gone with 6.0L and 3.73 gears, as I also have the buy the biggest engine you can get mentality.

Fuel mileage is something else to consider. I'm getting 13~14 mpg in mixed driving and 17~18 mpg on highway. I think folks are getting markedly better with 5.3L under normal conditions. Towing the travel trailer is only 8mpg on a good day...sometimes I think I should have invested in a diesel. If only GM had Cummins to go with that allison.

Doomsday · October 3, 2007

3.73's would net you better MPG too Gozer... I'm sure you already know that.

I net right around 15 mpg, which I think is preatty good considering I drive in preatty heavy traffic most of the time. Alot of MPG is how you drive as well... gotta go with the big 6.

SilveradoCJ7 · October 3, 2007

I went with the 6.0L and max trailer package (4.10 gears) since I tow a 27' travel trailer in PA mountains a few times a month in the camping season. If I wasn't towing that, I probably would have gone with 6.0L and 3.73 gears, as I also have the buy the biggest engine you can get mentality.

Fuel mileage is something else to consider. I'm getting 13~14 mpg in mixed driving and 17~18 mpg on highway. I think folks are getting markedly better with 5.3L under normal conditions. Towing the travel trailer is only 8mpg on a good day...sometimes I think I should have invested in a diesel. If only GM had Cummins to go with that allison.

umm, you ever hear of Duramax engines? Be happy we dont have the Power Stoke

tmoney · October 3, 2007

I would go with the 6.0 liter. Drove my dads new truck has 6.0l and compared to my 5.3l its a beast. If only i could afford one.

MS3DALE · October 3, 2007

I'm getting 15~15.5 in mixed driving and 17.5~18 on the highway.

Big Tool · October 3, 2007

Definitely go with the 6.0. Mine had a semi noticable feel when switching from v4-8 but that smoothed out at around 1000 miles. The 6.0 just performs better at all levels other than fuel economy. If you ever tow go with the 6.0, the 5.3 will be shifting it's a$$ off while the 6.0 steams away in OD. With the 6.0 you get heavy duty everything, breaks,tranny,rear end, and fuel milage will only be slightly less than the 5.3.

Gozer · October 3, 2007

I went with the 6.0L and max trailer package (4.10 gears) since I tow a 27' travel trailer in PA mountains a few times a month in the camping season. If I wasn't towing that, I probably would have gone with 6.0L and 3.73 gears, as I also have the buy the biggest engine you can get mentality.

Fuel mileage is something else to consider. I'm getting 13~14 mpg in mixed driving and 17~18 mpg on highway. I think folks are getting markedly better with 5.3L under normal conditions. Towing the travel trailer is only 8mpg on a good day...sometimes I think I should have invested in a diesel. If only GM had Cummins to go with that allison.

umm, you ever hear of Duramax engines? Be happy we dont have the Power Stoke

I'm definitely a GM truck person, but I don't think you can compare Duramax to Cummins when it comes to diesel engines in terms of dependability, longevity, and field-proven service. The combination of a Cummins motor with Allison tranny in a pick-up would be awesome.

Regardless, this post is about 5.3L vs. 6.0L, and I'll agree 100% that the 6.0L is a champ besides the mileage. I shouldn't complain about MPG thoug, as I'm getting about the same mileage out of this 367HP/375lb-ft 6.0L as I got out of my previous 255HP/330lb-ft 5.7L.

spartus · October 3, 2007

I'd go with the 6.0 too, if I were you. It seems that the 6.0 does better in city driving than the 5.3 does. Probably due to the VVT in the engine. My 5.3 CC gets about 13.5 mpg city driving, like an old lady, and 15-16 mpg on the highway. If I had to do it over again I'd go with the 6.0, but didn't know it was available at the time I got mine.

I recently read an article in Motor Trend where they were doing testing on a 1500 CC 4x4 with the 6.0 MAX package.. They loaded the truck with 1200 lbs of salt/dirt, and drove 400+ miles. They were able to get 18 mpg crusing at 75 mph. The guy said that the truck stayed in 4v mode most of the drive, and even held it while going up slight inclines on the highway.

Thats awesome considering my 5.3 only stayes into 4V mode about 10 seconds at a time.

cmoore74 · October 3, 2007

How are the e-brakes with the 4 wheel disk on the GMT900's with the VMax package? The reason I ask is usually the e-brakes are worthless when the rears are disk. Did they come up with a better e-brake? That's the only downfall I see to 4 wheel disk. Otherwise 4 wheel disk brakes stop on a dime.