GM 4.5L Diesel May Still Be Alive

[Ryan03]

Not trying to start anything here but have a real question so all you bow tie boys and girls calm down. How are the brakes on the current GM trucks? The last one I had, a 05 3500 Dmax, was not impressive. I never had any toubles with them in the 9 months I had it but my 04 F-250 Powerstroke had much better brakes. I know also the brakes on my uncles 97 2500 diesel Suburban were no comparison to the 99 F-350 Powerstroke I had at the time also.

My neighbor has a 07 3500 Classic Dmax and he has had 2 sets of warped rotors in about 60,000 miles. I have heard the 08's and later had better brakes but have not heard. He does use his truck. About 1/2 the miles are pulling a 14,000# 5th wheel.

So how are the brakes?

Chris

For what it's worth Chris, in my recent fleet experience, I have found that the GM HD's tend to have issues with the rear brake calipers sticking, leading to rotor failure. Those T55 Torex caliper slide bolts can be a real bear to get out as well. Blue wrench is usualy mandatory.

On the Ford SD's on the other hand, we have had issues with the brake caliper pins seizing in the caliper brackets, causing uneven pad wear and premature rotor failure. IMO, based upon my own experience, Ford can be pretty stingy with the grease on the caliper pins, so as a general practice, we now grease them pretty liberaly when we get a new SD in before putting it into service. So far so good, but time will tell.

The pedal feel is personal preference. I prefer the feel of the GM over the SD I owned in the past. That being said, I feel both trucks were acceptable when it came to brake performance.

 

[Diamondpilot]

For what it's worth Chris, in my recent fleet experience, I have found that the GM HD's tend to have issues with the rear brake calipers sticking, leading to rotor failure. Those T55 Torex caliper slide bolts can be a real bear to get out as well. Blue wrench is usualy mandatory.

On the Ford SD's on the other hand, we have had issues with the brake caliper pins seizing in the caliper brackets, causing uneven pad wear and premature rotor failure. IMO, based upon my own experience, Ford can be pretty stingy with the grease on the caliper pins, so as a general practice, we now grease them pretty liberaly when we get a new SD in before putting it into service. So far so good, but time will tell.

The pedal feel is personal preference. I prefer the feel of the GM over the SD I owned in the past. That being said, I feel both trucks were acceptable when it came to brake performance.

Thanks for the honest answer Ryan. So warped rotors are not the norm? I know on my neighbors 07 Dmax with about 60,000 miles he has had to have both rear seals replace. One at about 10,000 miles and one at about 50,000 miles. Could this lead to the brake problems or does the grease never get to it?

Lets be honest here. All the manufactures make good trucks. Everyone has a preference. Each is know for having a weak point. It all comes down to what you value and like in a truck. Having tried all them except Toyota in the last 6 years I have made up my mind.

Chris

 

[Dargo]

Then IMO, you are the exception with fuel economy. I get an honest 13.5 MPG in my Dmax. It's always at about 8,000 lbs and driven hard or towing. I did a rough survey more than a few times on the jobsite. The diesel guys were the same as me-all brands got ~13 MPG-they even showed me their readouts. The gas guys got ~11.

The last 3 diesel pickups I've had have been GM then Dodge and now Ford. I've averaged just over 13 mpg with each. To be fair, the Dodge did a bit better before I modified it to suit my needs. The original 160 hp or so just wasn't cutting it. I think flat empty I got just over 17 on the highway with it before mods. My F350 weighs just over 8100 pounds and I end up with just over 13 mpg both hand calculated as well as it's onboard trip computer. Towing 19k does sort of kill the mpg though.

 

[Lt CHEG]

GM claims the 5.3 on the 1/2 with active fuel management getting 20 mpg as the base engine. Going up 2 mpg and paying a premium up front for the diesel engine and then the $.30 extra for the fuel will not do it for me. If they could squeak 30 out of it then they would have something. Of course it will be better towing with a diesel, thats a no brainer but I would venture to guess if you took all the 1/2 tons sold in the last 10 years and figured out what percent of the time they tow it would be somewhere around 5-10%.

I would not be in line for any 1/2 ton diesel, no matter what brand, unless it got 50% better economy from the gas engine like the current diesel 3/4 and 1 ton trucks do.

Chris

It's been my experience that GM is very optimistic with the economy ratings of the current 5.3. I had a 2005 GMC Sierra 1500 Crew Cab and if I kept the speed to 70 to 71 I could get an honest to God 20 mpg on the highway. Driving my 2009 Silverado 1500 Crew cab I've yet to get better than 18.5 mpg anywhere. Both trucks were Z71's with the 5.3 V8 and 3.42 gears in the rear. The 2005 only had a 4spd auto whereas the 2009 has a 6 speed auto. The 2009 is noticeably more powerful but I just can't seem to get the mileage that I used to get. It is for that reason that I would strongly consider the 4.5 Diesel. Most of my driving is unloaded driving in an almost equal mix of highway and city driving. My average economy is about 14.5 and I really try to baby the gas pedal when starting out from a stop. If I could get that average to 18 to 19 mpg and get the highway economy up to 23 or so I'd be all over it. I don't keep vehicles for long, rarely do I even own the one that I'm trading in outright. So for me the higher resale of the diesel, especially coming from a low mileage truck would even out most of the higher up front cost. I'll also note that I'd be happy to break even and not even outright save money as long as everything came out in the wash. I'd be much happier though giving less of my money to the oil companies and to the Middle East. As unhappy as everyone was with the bailouts I'd rather give my money to "government motors" than to some company that artificially inflates the price of the product they sell so they can squeeze every last dollar out of their customers even though their product is a necessity.

 

[scoutcub]

I totally agree with what you are saying. The problem is whit the upfront cost of the diesel engine. I have a 04 F-250 and a 06 F-350 that we drive and with slight modifications both of these trucks get in the high 23 mpg range at around 75 mph and can still pull heavy loads if needed. The diesel option was about $6000 at the time.

Today the diesel is pushing $10,000 as a option on 2011 trucks. The price point is going to be a killer. Especially if you are only going from 20 to 25 mpg and not really getting a increase in tow rating over gas. On the 3/4 and 1 ton trucks its a different ball game because going from the base gas engine to the diesel you double the tow rating and fuel economy.

Chris

Chris -
Sorry to get off topic, but what mods did you do to your 06 PSD for improved MPG? I recently read on here "somewhere" about someone changing injectors and pump, and getting 1.5 or 2 MPG improvement, but I cannot find that thread again. I'm trying to squeeze all I can out of mine....

 

[pitt_md]

My 08 f250 with the 6.4 has averaged out to 14.7 mpg with mixed driving. This includes towing a couple horses 20 miles or so on the weekends. The more time spent in the city the worse it gets. It all comes down to how you drive your truck. I don't dirve mine very hard and I think that explains why I am getting a little better than average milage.

 

[Dargo]

My 08 f250 with the 6.4 has averaged out to 14.7 mpg with mixed driving. This includes towing a couple horses 20 miles or so on the weekends. The more time spent in the city the worse it gets. It all comes down to how you drive your truck. I don't dirve mine very hard and I think that explains why I am getting a little better than average milage.

That's by far the highest I've ever heard anyone state when it comes to MPG with a 6.4 PSD. In general most report single digit MPG when mostly in town or towing and just over 10 MPG or so overall. You drive downhill at all times?

 

[JESSE1]

I don't bother trying to manually figure my fuel mileage, it's not going to change it. I keep a check on the trip computer and it's showing an average of 12.2 mpg. This is an F-450 4x4 with 4.30 axle ratio, interstate driving and not pulling a trailer. Mileage is going to drop around 10 pulling a load. Speed definately kills the mileage on these trucks. I can get nearly 14 mpg if I keep my speed down to 55mph. When you run 70 or better the mileage drops straight down.

 

[Diamondpilot]

Chris -
Sorry to get off topic, but what mods did you do to your 06 PSD for improved MPG? I recently read on here "somewhere" about someone changing injectors and pump, and getting 1.5 or 2 MPG improvement, but I cannot find that thread again. I'm trying to squeeze all I can out of mine....

I just changed the intake to a MAC cold air kit. I also put 4" exhaust from the turbo down pipe back. All that is topped off with a Quadzilla Chip. I have down the same to all 3 of my Powerstrokes.

Chris

 

[Builder]

Makes me wonder how much an intake exhaust & chip would do to improve my fuel mileage. All the guys I know that run them average about 2-3 more mpg than I do.
I have no desire to increase HP with 360/650 stock from GM and I'm not messing with my warranty, either. Truck is a rocket with no mods, but when I hit 5yr/100K, I might have some fun.