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Chevrolet Suburban and GMC Tahoe MPG - Real World Numbers

185 messages,  Last post on Dec 25, 2010 at 9:20 PM

You are in the Chevrolet Suburban & Tahoe Forum.

What is this discussion about? Chevrolet Suburban, Chevrolet Tahoe Limited/Z71, Chevrolet Tahoe, Fuel Efficiency (MPG), SUV

Messages Page 16 of 19

#146 of 185 Re: FYI [catam] by johnny4016

Dec 29, 2006 (12:27 pm)

Replying to: catam (Oct 26, 2006 8:19 pm)
I noticed that you said your tire pressure is set at 50psi? I had mine set there when I first bought my Tahoe Z71. I have 2 Dunlops on the rear and 2 Remington on the front. They are 30570R16. Pretty decent tires. I have lowered my tire psi to 35 psi. I haven't noticed any real change in the mpg. Is there a reason why you keep yours at 50psi?

#147 of 185 2007 MPG for FFVs and recall #06162 by greggboston

Jan 02, 2007 (5:48 pm)

Wondering if anyone out there has had this recall applied (ECM reprogamming) and noticed better gas mileage with their 2007 Tahoe/Suburban with flex fuel engines ? The recall is dated 12/12/06 and GM is calling an "enhancement" (that's engineer-speak for "bug-fix") for FFV (flex fuel vehicles). Just had it applied to our Suburban and the AFM system seems to have been de-sensitized but I haven't been able to do a MPG check yet. Wondering if this is a fix for all the MPG complaints out there.
 
Regards,
- Gregg
Boston, Mass

#148 of 185 Re: FYI [johnny4016] by catam

Jan 03, 2007 (10:52 pm)

Replying to: johnny4016 (Dec 29, 2006 12:27 pm)
The quick answer is I don't know.
FYI, I drop my pressures to 35 PSI in the winter for improved traction in the snow. I know my mileage has dropped (last 2 tanks, 14.6 and 12.4 MPG). But this also coincides with majority of city driving and cold winter temps. I would guess that my mileage has dropped somewhat from the lower pressures, but like I said I don't know.
 
The reasons I keep it at 50 during the summer are: hopefully improved mileage, and ride quality when loaded.
 
One other point, your tires 305/ 70r16, will likely provide somewhat lower mileage for several reasons.
1) increased rolling resistance with wider tires.
2) unless you recalibrated your speedometer, you are actually traveling faster than your speedo states.

#149 of 185 Re: FYI [catam] by ahightower

Jan 04, 2007 (1:26 pm)

Replying to: catam (Jan 03, 2007 10:52 pm)
What's the maximum psi listed on the tire sidewall? 50 seems quite high to me. Isn't the recommended psi about 32? Even if 50 is not exceeding the tires' capacity, it may lead to "capping", where the center of the tread wears more quickly than it should. I used to overinflate the tires on my wife's Geo Metro (I know, not a good comparison), to 44 because that's what the tire said. I should have read the sticker in the doorjamb instead, which recommended somewhere mid-30's as I recall. Discount Tire said they were capping and recommended lowering my pressure. Just throwin' it out there.
 
I'm at least interested in what type of mileage difference you are seeing at 50 vs 35. I have a 2005 Yukon XL, with the 17" wheels, and I definitely feel a difference in ride quality at 36 psi vs 30, i.e., stiffer ride except when heavily loaded. Not a major discomfort, and worth the extra couple mpg, but I'm not sure I would want to go any higher and stiffer even if I could.

#152 of 185 reasons why 50PSI cold tire pressure is a bad idea by elias

Jan 09, 2007 (7:43 am)

Replying to: catam (Jan 03, 2007 10:52 pm)
imho 50 PSI cold pressure is unwise & unsafe.
i believe that handling (skidpad, for example) and emergency-stopping-distance will suffer substantially with such an excessive cold pressure.
additionally you are punishing the vehicle's suspension by pumping the tires beyond what the factory advises - the ride will suffer and the suspension components will wear out more quickly. (tie-rods, center-link, bushings, shocks, springs, for example). imho if you want better MPG, instead of buying a $50k SUV, buy a $30K SUV and a $20k hyper-mpg car, and concentrate the miles onto the car. i realize this is not an option for everyone, but it works for some folks. ttfn!

#153 of 185 Re: FYI [ahightower] by catam

Jan 13, 2007 (1:28 pm)

Replying to: ahightower (Jan 04, 2007 1:26 pm)
A little explanation.
My Sub is equipped with LT (Light Truck) tires not P (Passenger car) tires.
Most LT tires are capable of being inflated to 80PSI.
This is a very beneficial feature when tires are heavily loaded, (Ie. towing, loaded truck bed, etc.)
When I tow my boat I inflate my tires to 65 PSI in front, and 70 PSI in the rear. This makes a big difference to vehicle stability when towing especially at freeway speeds.
(I have towed my boat once at 50 PSI and there is a noticeable difference.)
 
As far as the "capping issue" I am aware of the potential for that problem, but I don't expect to see it as the Suburban weighs ~6500# empty. I do frequently examine my tires for signs of abnormal wear or other problems. (Anyone who tows regularly knows the importance of good tires.)
 
Like I said in previous post, I know my mileage is currently down with the lower pressures, but how much is from the tires alone is very difficult to say. (Other factors are mostly city driving and cold temps right now.)
 
As far as ride quality, I was pleased with the ride at 50 PSI, I notice a slightly smoother ride at 35 PSI, but not enough to change permanently. My wife drives this as her daily driver, and never comments about a change in ride regardless of where I put the pressures.

#154 of 185 Is this reasonable? by kipk

May 14, 2007 (6:27 am)

Considering getting a travel trailer in the 3500-4500 pound range.
 
Just kind of looking around at what type SUVs are available to perform this task.
 
A nephew has a 2004 Tahoe that is absolutely loaded with options, including 5.3L engine. He says his wife gets 15-17 daily driving and he has averaged as high as 28 on the road. But usually only averages 24 or so when maintaining 70 mph or so. Says he re sets the accumulated mileage numbers from the computer before starting the trip. He is in his low 30s of age and tends to drive a tad over the posted speed limits.
 
Does this sound reasonable or is he stretching the truth a bit?
 
Thanks,
 
Kip

#155 of 185 Re: Is this reasonable? [kipk] by ahightower

May 14, 2007 (11:33 am)

Replying to: kipk (May 14, 2007 6:27 am)
I'd say his wife's numbers are more realistic. There are literally dozens of posts in the forums about real world mpg and towing. Read up.
 
I will summarize what I've read over the past few months by saying that even the most optimistic don't claim much more than 20-21 on a good day. Most are right in line with the EPA estimates of 15 city, 19 highway. That's not great, but it's not so bad. Read up in the minivan forums and you'll see most of them don't do a whole lot better.
 
And if you need a tow vehicle, almost anyone would recommend a "real SUV" (truck frame) over a minivan or crossover. They may be rated for 4-5000 lbs, but that's the MAX rating which typically excludes the weight of all the passengers, cargo, even fuel. And have you seen a minivan or crossover pulling a heavy load and sagging in the rear? That's gotta really strain the motor, and can't be safe. Better to get a fullsize SUV rated at 7-9,000 lbs and be well within your limits, not approaching the maximum.

Messages Page 16 of 19

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