2500HD ZR2 500 Mile Review

[8ball_99]

What octane are you using?

I just run 87 in the 6.6. The owners manual says regular 87. Compression ratio on it is like 10.8. The 6.2 is 11.5 which is why it calls for a min of 91 octane. That said towing in the summer I plan to use 89. You add some extra heat and a load, 89 probably isn't a bad idea. But I think in the winter and just running around with out a load. Running Higher octane would be pointless.

That was actually something I took into consideration moving to the HD. I knew the mileage would be worse, But 87 is almost a dollar cheaper per gallon here. I did the math, if I only average 12mpg using 87, it's actually a few dollars cheaper then getting 15mpg with premium in the 6.2, lol. That is sort of the same deal with Diesel. It cost more per gallon. So it typically isn't much cheaper because a Duramax is probably going to only average a few more MPG. You factor in DEF, Filters, ect. You really have to get much better fuel mileage for it to save anything at the pump. If you tow a good amount that's really when diesels start to shine. They will usually get much better mileage while towing than gas. My duramax before only averaged around 15mpg over a tank of mixed driving. So when I went from it to a 6.2 that called for premium. My fuel cost was actually less on the 6.2 than it was on the Duramax. Diesel around here has been higher than Premium for a while now.

 

[112480]

I just run 87 in the 6.6. The owners manual says regular 87. Compression ratio on it is like 10.8. The 6.2 is 11.5 which is why it calls for a min of 91 octane. That said towing in the summer I plan to use 89. You add some extra heat and a load, 89 probably isn't a bad idea. But I think in the winter and just running around with out a load. Running Higher octane would be pointless.

That was actually something I took into consideration moving to the HD. I knew the mileage would be worse, But 87 is almost a dollar cheaper per gallon here. I did the math, if I only average 12mpg using 87, it's actually a few dollars cheaper then getting 15mpg with premium in the 6.2, lol. That is sort of the same deal with Diesel. It cost more per gallon. So it typically isn't much cheaper because a Duramax is probably going to only average a few more MPG. You factor in DEF, Filters, ect. You really have to get much better fuel mileage for it to save anything at the pump. If you tow a good amount that's really when diesels start to shine. They will usually get much better mileage while towing than gas. My duramax before only averaged around 15mpg over a tank of mixed driving. So when I went from it to a 6.2 that called for premium. My fuel cost was actually less on the 6.2 than it was on the Duramax. Diesel around here has been higher than Premium for a while now.

Same here...well shoot...from Mobile,AL all the way the Roanoke,VA..Diesel is high 3's...to low $4.00-ish/gallon....man 87 is #MORE than a $1/gallon cheaper than diesel...I figured you would say 87...but thought that you might go 89 regardless if you are towing or not because price doesn't really jump until after 89oct....I remember being a teenager in mid 90's back in Atlanta...when Quiktrip came into town...gas was #LITERALLY 10 #CENT Between each other...there was no need to "wonder" how much 89 pr 93 was...all you needed to know was how much 87oct was

 

[8ball_99]

Same here...well shoot...from Mobile,AL all the way the Roanoke,VA..Diesel is high 3's...to low $4.00-ish/gallon....man 87 is #MORE than a $1/gallon cheaper than diesel...I figured you would say 87...but thought that you might go 89 regardless if you are towing or not because price doesn't really jump until after 89oct....I remember being a teenager in mid 90's back in Atlanta...when Quiktrip came into town...gas was #LITERALLY 10 #CENT Between each other...there was no need to "wonder" how much 89 pr 93 was...all you needed to know was how much 87oct was

I'm not a mechanic by any means, But I've been friends with several of them. If a motor is setup to run 87, running 91 or 93 is not just a waste. It can actually give you less power and worse mileage. Higher octane fuel doesn't actually ignite as well in a engine not setup for it. My sister use to own a motor cycle shop. And the mechanics there would die laughing when guys would bring their bikes in saying they mostly only put racing gas in from the local sunoco in their stock bike.

Under load, especially in hotter weather, Jumping up one fuel grade isn't a bad idea. Vehicles all have knock sensors now. They should protect them selves by pulling timing if the fuel starts going off early. Doesn't hurt to take extra precautions though.

 

[securityguy]

I'm not a mechanic by any means, But I've been friends with several of them. If a motor is setup to run 87, running 91 or 93 is not just a waste. It can actually give you less power and worse mileage. Higher octane fuel doesn't actually ignite as well in a engine not setup for it. My sister use to own a motor cycle shop. And the mechanics there would die laughing when guys would bring their bikes in saying they mostly only put racing gas in from the local sunoco in their stock bike.

Under load, especially in hotter weather, Jumping up one fuel grade isn't a bad idea. Vehicles all have knock sensors now. They should protect them selves by pulling timing if the fuel starts going off early. Doesn't hurt to take extra precautions though.

Exactly...it kills me to see people post on forums that they use 91 or 93 on a vehicle that only requires 87 and they think they are doing something good.

 

[8ball_99]

Exactly...it kills me to see people post on forums that they use 91 or 93 on a vehicle that only requires 87 and they think they are doing something good.

It's partly the oil industries fault. With names like plus and premium people automatically assume it's better. More octane has to be better right? Average person has no idea that number just makes it harder to ignite in a engine. For it to burn proper it needs more pressure and spark. Lol, To be fair when I was 16, I use to dump a bottle of octane booster in my stock 350 on Friday nights. I thought I was adding more power, haha. My truck would even back fire some. Which I thought it was cool. Come to find out that was just unburnt fuel making its way to the exhaust. Wondered why I'd foul spark plugs from time to time.

 

[AXE]

Yeah but back then you could tune the carb, air intake, valves, or change pistons and get more power. Now you have to be a computer programmer and wait for someone to crack the code.

 

[112480]

I'm not a mechanic by any means, But I've been friends with several of them. If a motor is setup to run 87, running 91 or 93 is not just a waste. It can actually give you less power and worse mileage. Higher octane fuel doesn't actually ignite as well in a engine not setup for it. My sister use to own a motor cycle shop. And the mechanics there would die laughing when guys would bring their bikes in saying they mostly only put racing gas in from the local sunoco in their stock bike.

Under load, especially in hotter weather, Jumping up one fuel grade isn't a bad idea. Vehicles all have knock sensors now. They should protect them selves by pulling timing if the fuel starts going off early. Doesn't hurt to take extra precautions though.

True...and I'm also into racing...have been 20+years so I KNOW #EXACTLY what you mean by octane differences and them not being neccessary depending on how the motor is built(or not built)and truely can hurt performance etc with a higher octane that the motor isn't really setup for...

I was just wondering which one you use more daily for the ZR2 HD

 

[112480]

Hey guys...anyone think GM #MAY do a 3500 ZR2

 

[8ball_99]

True...and I'm also into racing...have been 20+years so I KNOW #EXACTLY what you mean by octane differences and them not being neccessary depending on how the motor is built(or not built)and truely can hurt performance etc with a higher octane that the motor isn't really setup for...

I was just wondering which one you use more daily for the ZR2 HD

It's been cold here and I haven't towed yet as I just hit 1200 miles today. Waiting for 1500 miles and a oil change before I tow anything. So far during break in running 87, I've averaged 13mpg over the 1200 miles. According to the DIC anyway. Seems about right. I filled up today with half a tank and my trip showed 230ish miles. On the way back from Ohio I had around 520 mile range. Was getting 14-15. Once it gets a little more broke in I probably will try a couple tanks of 89. Just to see if the truck likes it better. My 6.2 did better on Shell gas for what ever reason. I haven't even tried shell in the HD yet.

 

[AXE]

Hey guys...anyone think GM #MAY do a 3500 ZR2

Just get a LTZ and a 4 inch Cognito lift with Elka suspension. Same truck, nicer front clip.

Cognito 4-Inch Elite Lift Kit with Elka 2.5 Reservoir Shocks for 20-24 Silverado/Sierra 2500/3500 2WD/4WD

Each Kit Features: Yields 4-inches of front lift and 2 inches of rear lift Cognito Block and U-Bolt Kit SM Series Ball Joint Upper Control Arms Patented Pitman and Idler Arm Support Kit Elka 2.5 Performance Series Remote Reservoir Shocks Maintains Adequate Droop Travel for Superior Ride Quality...

cognitomotorsports.com

 

[112480]

Just get a LTZ and a 4 inch Cognito lift with Elka suspension. Same truck, nicer front clip.

Cognito 4-Inch Elite Lift Kit with Elka 2.5 Reservoir Shocks for 20-24 Silverado/Sierra 2500/3500 2WD/4WD

Each Kit Features: Yields 4-inches of front lift and 2 inches of rear lift Cognito Block and U-Bolt Kit SM Series Ball Joint Upper Control Arms Patented Pitman and Idler Arm Support Kit Elka 2.5 Performance Series Remote Reservoir Shocks Maintains Adequate Droop Travel for Superior Ride Quality...

cognitomotorsports.com

Nice lift kit! But man IMO the ZR2 front clip is way Nicer than the LTZ

 

[Busa Dave]

It's partly the oil industries fault. With names like plus and premium people automatically assume it's better. More octane has to be better right? Average person has no idea that number just makes it harder to ignite in a engine. For it to burn proper it needs more pressure and spark. Lol, To be fair when I was 16, I use to dump a bottle of octane booster in my stock 350 on Friday nights. I thought I was adding more power, haha. My truck would even back fire some. Which I thought it was cool. Come to find out that was just unburnt fuel making its way to the exhaust. Wondered why I'd foul spark plugs from time to time.

I am an oil and gas producer. The Octane thing is very complicated. Depending on your altitude the Octane rating for "Super" can be 94 to 90. Additionally, to run higher octane fuel in a modern automotive engine that does not require it will not harm it because the timing is adjusted constantly by the vehicle however you are wasting money. Actually, people think there is more energy in the higher-octane fuel and there is not there is actually a slightly less amount of energy.

Higher Octane fuel will withstand spontaneous detonation better allowing the use of higher compression engines.

Hope this helps some to understand this subject better.

 

[112480]

I am an oil and gas producer. The Octane thing is very complicated. Depending on your altitude the Octane rating for "Super" can be 94 to 90. Additionally, to run higher octane fuel in a modern automotive engine that does not require it will not harm it because the timing is adjusted constantly by the vehicle however you are wasting money. Actually, people think there is more energy in the higher-octane fuel and there is not there is actually a slightly less amount of energy.

Higher Octane fuel will withstand spontaneous detonation better allowing the use of higher compression engines.

Hope this helps some to understand this subject better.

Correct sir!!!

 

[PL1HD1]

Hey guys...anyone think GM #MAY do a 3500 ZR2

I wish … Im trading my 21 LTZ 3500 next week on a ZR2 HD . I’m hoping it won’t be an issue usually tow Travel trailer that weighs in at about 9-10k but tow it all over the country . Shouldn’t be an issue at least on paper . I’m hoping I don’t regret the step down to a 2500 .

 

[AXE]

I wish … Im trading my 21 LTZ 3500 next week on a ZR2 HD . I’m hoping it won’t be an issue usually tow Travel trailer that weighs in at about 9-10k but tow it all over the country . Shouldn’t be an issue at least on paper . I’m hoping I don’t regret the step down to a 2500 .

10k isn't much weight. I've towed up to 15k with lifted 2500HDs for 20 years, no problems. I've towed my TT weighing in about 14K loaded with sxs and gear hundreds of miles per trip and it tows great. Just add some air bags and you'll be ready.

 

[PL1HD1]

10k isn't much weight. I've towed up to 15k with lifted 2500HDs for 20 years, no problems. I've towed my TT weighing in about 14K loaded with sxs and gear hundreds of miles per trip and it tows great. Just add some air bags and you'll be ready.

Yea I’m not towing that heavy but we sometimes do a lot of distance . The 3500 is solid towing for sure . Last summer we went from Va to Yellowstone in Wyoming and did the Grand circle of parks and came back thru New Mexico and Texas did about 8k miles in 19 days most of it with TT in tow . This summers trip is Maine into Canada and back around I’ll figure out real quick how it compares . Side Note on my long Trip I noticed fuel mileage falls off above 65 or so I only averaged around 9.5-10 on that long trip last summer towing

 

[AXE]

Yea I’m not towing that heavy but we sometimes do a lot of distance . The 3500 is solid towing for sure . Last summer we went from Va to Yellowstone in Wyoming and did the Grand circle of parks and came back thru New Mexico and Texas did about 8k miles in 19 days most of it with TT in tow . This summers trip is Maine into Canada and back around I’ll figure out real quick how it compares . Side Note on my long Trip I noticed fuel mileage falls off above 65 or so I only averaged around 9.5-10 on that long trip last summer towing

I could get 10-12 mpg on my previous lifted 2500HD Duramax running 35s towing 12-13.5k running 70+mph. The sweet spot for me was 68 mph if I was trying to get best mileage and could get 12.5+mpg. I expect to get same with my 24.

Lifted trucks like these with big tires costs you 1.5-2 mpg. They are mostly poser rigs with decent offroad and towing capabilities.

Wind kills mileage the most in these lifted trucks with big tires, towing high profile trailers. I got 8.5 mpg a couple times with headwind/crosswind.

 

[PL1HD1]

I could get 10-12 mpg on my previous lifted 2500HD Duramax running 35s towing 12-13.5k running 70+mph. The sweet spot for me was 68 mph if I was trying to get best mileage and could get 12.5+mpg. I expect to get same with my 24.

Lifted trucks like these with big tires costs you 1.5-2 mpg. They are mostly poser rigs with decent offroad and towing capabilities.

Wind kills mileage the most in these lifted trucks with big tires, towing high profile trailers. I got 8.5 mpg a couple times with headwind/crosswind.

Headwind definitely knocked me down on the way out last summer . Also my 21 has a small lift and bigger tires that knocked the mileage down when I installed it . I hear people all the time to get crazy fuel mileage numbers that I never see . Unloaded highway cruising I average around 18

 

[112480]

10k isn't much weight. I've towed up to 15k with lifted 2500HDs for 20 years, no problems. I've towed my TT weighing in about 14K loaded with sxs and gear hundreds of miles per trip and it tows great. Just add some air bags and you'll be ready.

And see man I have PLENTY of coworkers in the same situation...2500 HD towing around 15-16k no problems with airbags for YEARS...Now they are diesel...but the new gasser should be a problem

 

[AXE]

Headwind definitely knocked me down on the way out last summer . Also my 21 has a small lift and bigger tires that knocked the mileage down when I installed it . I hear people all the time to get crazy fuel mileage numbers that I never see . Unloaded highway cruising I average around 18

Yep, I think that sounds about right. Ib would get 15.5-16.5 mpg running around town mixed streets and freeway. Other guys with no lift 18ish. That's about what I get with the Ram 2500 Cummins truck I use for work too, no lift running 285s. I feel like that's not bad for 8000lbs trucks with no aero.