Lookin At A 6.2

retoxtony · July 23, 2009

Been looking at a new truck, i just cant decide for sure if its what i need and i had a few questions. The truck is a 09 sierra allterrain with the 6.2 engine. My biggest concern with this truck is the fuel mileage. I've read a few other posts of guys saying its not too bad but i still wonder if the 5.3 with a tune for some more power would be a better option. My other big concern is that i know this engine likes 93 octane. Just kinda wondering how much difference in performance and mileage i'll see if i only run 87 through it.

z7107sierra · July 23, 2009

Been looking at a new truck, i just cant decide for sure if its what i need and i had a few questions. The truck is a 09 sierra allterrain with the 6.2 engine. My biggest concern with this truck is the fuel mileage. I've read a few other posts of guys saying its not too bad but i still wonder if the 5.3 with a tune for some more power would be a better option. My other big concern is that i know this engine likes 93 octane. Just kinda wondering how much difference in performance and mileage i'll see if i only run 87 through it.

From what I've seen and heard your probly going to get around 14-17..But if you really want the extra power do it..That engine is going to last much longer than a chipped up a 5.3...I mean your talking almost another 100hp..You'll never get that from a 5.3 by puting a chip in it..

Porter_ · July 23, 2009

Been looking at a new truck, i just cant decide for sure if its what i need and i had a few questions. The truck is a 09 sierra allterrain with the 6.2 engine. My biggest concern with this truck is the fuel mileage. I've read a few other posts of guys saying its not too bad but i still wonder if the 5.3 with a tune for some more power would be a better option. My other big concern is that i know this engine likes 93 octane. Just kinda wondering how much difference in performance and mileage i'll see if i only run 87 through it.

From what I've seen and heard your probly going to get around 14-17..But if you really want the extra power do it..That engine is going to last much longer than if you chipped up a 5.3...I mean your talking almost another 100hp..You'll never get that from a 5.3 by puting a chip in it..

^^^ that's pretty unsubstantiated.

retoxtony, in the grand scheme of things i would say the fuel economy is going to be negligible. i get 17 highway with my 4.8. i would easily put up with 15 highway if i could afford the 6.2. my advice is to get the largest engine you can afford. also, if the 6.2 requires 93 octane it's to avoid pre-ignition...so use 93 octane. i haven't bothered to look into whether or not the 6.2 actually requires 93, are you certain of this?

music · July 23, 2009

If I recall correctly, running 87 octane drops the power/torque about 5 to 10% on the 6.2.

Edit: I tried to find where I read that range, but no luck. So... don't give it much credence without a good reference or someone else confirming it.

z7107sierra · July 23, 2009

Been looking at a new truck, i just cant decide for sure if its what i need and i had a few questions. The truck is a 09 sierra allterrain with the 6.2 engine. My biggest concern with this truck is the fuel mileage. I've read a few other posts of guys saying its not too bad but i still wonder if the 5.3 with a tune for some more power would be a better option. My other big concern is that i know this engine likes 93 octane. Just kinda wondering how much difference in performance and mileage i'll see if i only run 87 through it.

From what I've seen and heard your probly going to get around 14-17..But if you really want the extra power do it..That engine is going to last much longer than if you chipped up a 5.3...I mean your talking almost another 100hp..You'll never get that from a 5.3 by puting a chip in it..

^^^ that's pretty unsubstantiated.

retoxtony, in the grand scheme of things i would say the fuel economy is going to be negligible. i get 17 highway with my 4.8. i would easily put up with 15 highway if i could afford the 6.2. my advice is to get the largest engine you can afford. also, if the 6.2 requires 93 octane it's to avoid pre-ignition...so use 93 octane. i haven't bothered to look into whether or not the 6.2 actually requires 93, are you certain of this?

All I meant by that was by installing a chip on a 5.3 your only going to get a few extra ponies and if he plans on keeping the truck 100,000 miles plus I wouldnt be installing any chips..From what my Dealer told me it will void the warrenty,& its going to add alot more strain on the drivetrain & over time your going to start running into problems..My GM Mechanic says he's seen it happen over and over..but if you plan on trading in every couple years I wouldnt worry about it..If your planning on keeping the truck long term..100k + you would probly be better off just buying the truck with the larger engine vs trying to make a 5.3 like a 6.2... Theres no way chipping & tuning & puting on a dual exhuast would ever bring a 5.3 up to 425hp without major changes..If I'm wrong someone please enlighten me & I"ll eat my words..

I think you would be much happier with the 6.2...Try out both..Gas Mileage isnt going to be alot worse..If you really want power the 6.2 is probly going to be cheaper in the long run vs trying to get more out of a 5.3..Thats just my .02

Darkanion · July 23, 2009

Fuel mileage is very dependent on driving style. Around town, with traffic, red lights, idiot drivers, etc., I get about 14-15 mpg on my 2007 Sierra Denali (with the 6.2). On the highway, just cruising, going relatively easy on the throttle (speeding up & slowing down), though.. If I keep it below 80, I can usually get around 20 mpg, +/- a little bit.

Mine is 2WD/RWD, though.. So, my mileage #'s will be a little higher than what you'd see on a 4x4.

I've always run Premium, so I can't answer your questions re: not running Premium. I have "heard" that there is a reduction in performance and fuel mileage.

Personally, I wouldn't (and don't) skimp on the extra 20-30 cents per gallon of gas to go into a $40k+ vehicle.. If it's that big of an issue, then get the 5.3, get it tuned, and be happy with it!

huero626 · July 23, 2009

If your worried about fuel mileage I don't think you should be looking into getting a truck IMO. If your really want the power of a 6.2L you should go for it, a tuned 5.3L with exhaust & cold air intake will not feel as powerful as a 6.2L. IMO get the bigger engine that u can so that when u sell it you get more money for it and you will be happier with the bigger engine. I wanted a 6.2L when I bought my truck but at that time it was only available in the Sierra Denali, but I wanted a extended cab standard bed truck and the only available engine was the 6.0L. With the mods I have done to my truck I'm pretty sure I will hang with a 6.2L.

C. Charles Hahn · July 23, 2009

I'll put it this way: I have a Sierra All-Terrain with the 5.3L, and there are definitely times I wish I'd opted for the larger (6.0L VMax at the time) engine option.

androgelrx · July 23, 2009

If you want just power, get a Tundra and put a supercharger on it. It'll get around 500hp and it will still be cheaper than the chevy 6.2l. Coming from a Tundra, the 5.3l is ok but I still love the chevy truck. I do miss the power of the tundra. There are +/- with every truck. If the Tundra had a full boxed frame, I wouldn't have gotten a Chevy. But I really enjoy my new Silverado. I'm just going to keep it stock.

huero626 · July 23, 2009

If you want just power, get a Tundra and put a supercharger on it. It'll get around 500hp and it will still be cheaper than the chevy 6.2l. Coming from a Tundra, the 5.3l is ok but I still love the chevy truck. I do miss the power of the tundra. There are +/- with every truck. If the Tundra had a full boxed frame, I wouldn't have gotten a Chevy. But I really enjoy my new Silverado. I'm just going to keep it stock.

On my V-Max with minor bolts and a supercharger my Chevrolet could also get around 500hp.

retoxtony · July 23, 2009

Thanks for all the responses guys. I was wondering about the octane rating as i live in a very small town where our gas station only offers regular 87 octane fuel. I'm really not that worried about having huge power, i just wanted a little more than what the 5.3 has. I guess i'll have to do some more looking around.

Stevens03 · July 23, 2009

Well, the 6.2 does NOT require 93 octane, it will run just fine on 87. Also, with the 6-speed trans and 3.42 gears you can easily get 18-21mpg with it on the highway. Several have reported good mileage on the highway. In town,... well thats all about how hard you want to hammer down between stop lights. As low as 12 and with easy to normal driving 14-15mpg.

Not bad for a 403hp truck. My 6.0 Vmax just got 18.6mpg on a 780 mile trip. I know the 6.2 6-speed can get better. I wouldn't hesitate if the price was right.

Darkanion · July 23, 2009

From page 378 of the Owner's Manual on my '07 SD :

Gasoline Octane

Use premium unleaded gasoline with a posted octane rating of 91 or higher. You can also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle's acceleration could be slightly reduced, and you might notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you might notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

SO.. According to the owner's manual, you should run 87 or higher.. you may notice some knocking.. and you're performance could be impacted.. OR run 91 or higher and not worry about it.

If you don't mind my asking, where the heck are you located that only has regular unleaded?? Even the small towns I've gone through in Colorado, Wyoming, etc., if they have a gas station, they usually have multiple grades (or the least two grades) of fuel. It just seems odd to me that they "only" have 87..

With the 6.2's "recommending" premium.. and you want "a little more power than the 5.3's," I'd suggest you try to find a deal on a VMax.. Someone else can chime in and correct me, but I don't think they "recommend" premium for the 6.0's..

Bowtie2Sierra · July 23, 2009

Thanks for all the responses guys. I was wondering about the octane rating as i live in a very small town where our gas station only offers regular 87 octane fuel. I'm really not that worried about having huge power, i just wanted a little more than what the 5.3 has. I guess i'll have to do some more looking around.

Maybe a 5.3 with a tune would satisfy you? The 5.3 is all I need and I am very happy with it.

I bought my truck at a good price a year ago and was recently offered the same money I paid for it. So I've been kicking around ordering a '10 if I can find decent pricing. FWIW, if I end up selling the '08, I'll go with the 6.2 the next time around assuming I can get it in a SLE. Otherwise, I'll go back to the 5.3. Just another perspective.

kutu · July 23, 2009

I have a 6.2L 2007 SD AWD. On a recent 2,400 mile trip to Canada and back I got 19.3 mpg as calculated from actual gas receipts (the DIC said 19.9mpg). I always use 93 octane.

I'm retired and live in a small. Around town is mostly really short trips, and I get mpg in the mid-teens. When I did travel to a job every day (50 miles) my combined mileage was a little over 18mpg.