adventurenali92
Full Access Member
Didn’t even catch that haha. Was supposed to say Subaru*Submarine Outback?
6.2 to 5.3
- Thread starter Cbark2305
- Start date
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Tonyrodz
Resident Resident
Damn Auto Correct got another victim lol. Just busting your chops.
intheburbs
Full Access Member
But you're ok spending a lot more on an engine swap?
You said it's not a daily driver. Do some math to figure out how much you'd save in gas switching out the motor, compare to the cost of the swap, and I guarantee your ROI would be well over 10 years.
The Denali can run on midgrade or even regular. Just keep an ear out for pinging/detonation.
Or, if you really want to have fun, throw in some E85 and watch the mileage plummet to about 7-8.
Basics
TYF Newbie
FWIW, kind’ve off topic but I think 2wd mode versus AWD or auto mode affects your mpg’s just as much. City/hwy combined, It’s about a 2 mpg difference, which is noticeable for me when your under 15 mpg. Not sure what your options are in that regard
Avalanchediver
Member
- Joined
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Had a 5.3 in my 2007 Suburban, my 2015 Yukon XL 6.2 gets better mileage in every category. Plus it can pull a trailer at highway speed.
kbuskill
***CAUTION*** I do my own stunts!
I don't believe the Denalis have the ability to select 2wd.
kbuskill
***CAUTION*** I do my own stunts!
Kind of apples to oranges since the '15 is an LT engine instead of an LS.
a custom tune will definitely make it not a pig anymore and bring the gas mileage up with you drive it right. my 08 escalade has a cam, headers, cai, and tune and it's constantly gets 13-14. i do drive a lot of highway but i don't drive it easy. its awd too
Eod1
If you see me running, I would try to keep up.
Do you pull any boats or trailers with it. If I did I would want the 6.2. My 2012 5.3 gets 15 to 16 in city and 18 to 20 on highway. Now I have done some things to mine that may have helped out a little. That in mind if you load it down with people and pull a big boat, the 6.2 with some upgrades would be my engine.
swathdiver
Full Access Member
K2s are selectable, not full time AWD anymore like GMT900.
Depending on the cost, running E85 may cost less per mile in city driving.
My truck runs more efficient in heavy city driving and idling on E85 compared with 93 octane gasoline. It also gets better mpgs while towing on E85 in the city.
The tune is worth the price of the AutoCal or you could take a drive down to Baton Rouge and drive back with a 5.3! I'm sure Chris will let you sleep in his barn while he swaps the engines! LOL
iamdub
Full Access Member
Absolutely. I can't make the trip up there, but he's welcome to come to me. My shop is well-insulated and very warm, I've slept in there a few times.
My Tahoe is a weekend toy so I'll bear his 6.2's MPG burden for the extra power.
992dr
Full Access Member
That's a first, 6.2 to a 5.3
I'd love a 6.2 and the MPGs that goes with it
I'd love a 6.2 and the MPGs that goes with it
swathdiver
Full Access Member
6.2s are also used in the Denali and in a handful of Suburbans and Tahoes.
I like it for the increased fuel economy and keeping my fuel system clean. But the motor likes E85 the best and is run with that mostly.
Actually, these ls motors run better on super. They have a higher compression ratio and the “premium” super, higher octane, whatever you want to call it, gives it a better combustion which we all know.. a better, more complete, clean burn equals more horses and better mileage
iamdub
Full Access Member
"Premium" has nothing to do with the cleanliness of the fuel in regards to what it's supposed to reference, which is the higher octane level. Yes, some brands may mix in extra detergents or whatever to their premium and not in their regular, but I doubt they go through the trouble. It's really all about octane and to sell it, they call it all of these names that make you feel like you're doing your engine and fuel system a favor. Pouring a fuel into your tank labeled "Premium" or "Super" or "Ultra" or "V-Power" (V-Taaaaaaaaaaack!!! ) does not suddenly make your car a high-performance machine. It also does not mean your engine is burning cleaner or more complete. In fact, it could be the opposite. If the engine can't benefit from higher octane by it's mechanical design or tuning, then it won't. A fuel's octane rating is basically how much that fuel can be compressed before it spontaneously ignites. Lower octane ignites more easily, higher octane takes more pressure to make it ignite. Another way to word it is that higher octane is less "flammable" than lower octane.
So, how can a fuel that's MORE resistant to burning burn more completely and cleaner? It doesn't. In general, the LS engine platform, although rated for 87 octane, is mechanically designed to run more optimally on 89 or higher. I experience noticeable differences in performance when running 89 and there may be even more when on 91-93. This doesn't mean the fuel is making more power. It's because the compression ratio (dynamic more so than static) and stock tuning maps are a hair too aggressive for 87. On hot days or with crappy gas or when under elevated loads or even with just more spirited driving, the low octane gas that ignites so easily, well, it ignites TOO easily. This is what leads to detonation ("pinging", "spark knock", etc.). The PCM detects this via the knock sensors and retards the timing, which reduces engine power. For someone that drives it forever on 87 may be pleasantly surprised if they tried 89 or higher. To them, it would be like they just filled up with a tank of "supercharged gasoline" when all they did was allow the engine to operate optimally and produce the power it was always meant to produce in the first place. In an engine that is NOT as "high-strung" (lower compression, less aggressive timing, etc.), running a fuel that is more reluctant to burn (high octane) at least means reduced power and likely unburnt fuel, which means dirtier combustion chambers and eventually clogged cats. A fuel-injected engine constantly monitors and adjusts the fueling so the unburnt fuel problem is mildly mitigated, but it still occurs, especially under WOT.
Personally, I'd rather let the engine run how it should and not be hindered by the PCM reacting in efforts to keep the engine from self-destructing.
) does not suddenly make your car a high-performance machine. It also does not mean your engine is burning cleaner or more complete. In fact, it could be the opposite. If the engine can't benefit from higher octane by it's mechanical design or tuning, then it won't. A fuel's octane rating is basically how much that fuel can be compressed before it spontaneously ignites. Lower octane ignites more easily, higher octane takes more pressure to make it ignite. Another way to word it is that higher octane is less "flammable" than lower octane.So, how can a fuel that's MORE resistant to burning burn more completely and cleaner? It doesn't. In general, the LS engine platform, although rated for 87 octane, is mechanically designed to run more optimally on 89 or higher. I experience noticeable differences in performance when running 89 and there may be even more when on 91-93. This doesn't mean the fuel is making more power. It's because the compression ratio (dynamic more so than static) and stock tuning maps are a hair too aggressive for 87. On hot days or with crappy gas or when under elevated loads or even with just more spirited driving, the low octane gas that ignites so easily, well, it ignites TOO easily. This is what leads to detonation ("pinging", "spark knock", etc.). The PCM detects this via the knock sensors and retards the timing, which reduces engine power. For someone that drives it forever on 87 may be pleasantly surprised if they tried 89 or higher. To them, it would be like they just filled up with a tank of "supercharged gasoline" when all they did was allow the engine to operate optimally and produce the power it was always meant to produce in the first place. In an engine that is NOT as "high-strung" (lower compression, less aggressive timing, etc.), running a fuel that is more reluctant to burn (high octane) at least means reduced power and likely unburnt fuel, which means dirtier combustion chambers and eventually clogged cats. A fuel-injected engine constantly monitors and adjusts the fueling so the unburnt fuel problem is mildly mitigated, but it still occurs, especially under WOT.
Personally, I'd rather let the engine run how it should and not be hindered by the PCM reacting in efforts to keep the engine from self-destructing.
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swathdiver
Full Access Member
I recently learned that Top Tier fuels have the additives in all grades of fuel, not just the high test.
We've run 38 tanks of fuel so far this year and 20 of them have been E85, the motor loves it.
We've run 38 tanks of fuel so far this year and 20 of them have been E85, the motor loves it.
iamdub
Full Access Member
That's what I meant by the fuel plants not singling out one grade over another when mixing in their additives. For one, it'd complicate the manufacturing. I mean, they really only make two grades- regular and "super/premium". The mid-grade is simply a blend of the two. Also, the Top Tier producers want all grades of their fuel with their "secret recipes" to be as effective as the other. Otherwise, only those willing to pay for premium, whether it's beneficial to them or not, would be getting that producer's actual top tier fuel and those with vehicles designed to run on cat piss are left with... cat piss. So, all grades contain the same additives and the octane rating is a completely separate factor. The marketers have just blurred the lines between the two to increase sales of the higher-priced stuff.
If I'm ever in need of a fill-up and there's an E-85 station nearby, I'd give it a shot. I know the MPG would be worse but the performance should be the same or better than that of the 89 or higher octane since E-85 has an octane rating of 108. So, since mine needs 89 octane or better, I can ignore the regular grade and base my cost comparison to 89 or 91 octane to E-10 or E-0. The cost per mile of E-85 should surely be cheaper to run while providing the same performance.
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swathdiver
Full Access Member
E85 gives about fifteen free horsepower and a little more than that of torque. There are a couple of stations in Baton Rouge, don't know how close you are to them last time I looked. If the price drops below $2 a gallon, my truck will be almost as inexpensive to run as my daughter's Kia.
Some top tier brands deliver terrible fuel mileage compared to others like Shell. Mobil and Chevron deliver the best mpgs in my area.
Not talking about ‘cleaning the engine with premium’ a higher compression engine, like the ls, benefits from higher octane. Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures. Compression ratios also factor into cylinder pressures. Higher ratios cause highercylinder pressures and therefore cause the engine to be more susceptible to pre-detonation or knock."Premium" has nothing to do with the cleanliness of the fuel in regards to what it's supposed to reference, which is the higher octane level. Yes, some brands may mix in extra detergents or whatever to their premium and not in their regular, but I doubt they go through the trouble. It's really all about octane and to sell it, they call it all of these names that make you feel like you're doing your engine and fuel system a favor. Pouring a fuel into your tank labeled "Premium" or "Super" or "Ultra" or "V-Power" (V-Taaaaaaaaaaack!!!
So, how can a fuel that's MORE resistant to burning burn more completely and cleaner? It doesn't. In general, the LS engine platform, although rated for 87 octane, is mechanically designed to run more optimally on 89 or higher. I experience noticeable differences in performance when running 89 and there may be even more when on 91-93. This doesn't mean the fuel is making more power. It's because the compression ratio (dynamic more so than static) and stock tuning maps are a hair too aggressive for 87. On hot days or with crappy gas or when under elevated loads or even with just more spirited driving, the low octane gas that ignites so easily, well, it ignites TOO easily. This is what leads to detonation ("pinging", "spark knock", etc.). The PCM detects this via the knock sensors and retards the timing, which reduces engine power. For someone that drives it forever on 87 may be pleasantly surprised if they tried 89 or higher. To them, it would be like they just filled up with a tank of "supercharged gasoline" when all they did was allow the engine to operate optimally and produce the power it was always meant to produce in the first place. In an engine that is NOT as "high-strung" (lower compression, less aggressive timing, etc.), running a fuel that is more reluctant to burn (high octane) at least means reduced power and likely unburnt fuel, which means dirtier combustion chambers and eventually clogged cats. A fuel-injected engine constantly monitors and adjusts the fueling so the unburnt fuel problem is mildly mitigated, but it still occurs, especially under WOT.
Personally, I'd rather let the engine run how it should and not be hindered by the PCM reacting in efforts to keep the engine from self-destructing.
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