A real before/after analysis of heavier AT tires w/ level vs. stock

[crushNchowda]

Well I think I'm taking these off my truck & swapping them out for P rated Nitto Terra Grapplers in the same 275/60r20 size. My MPG dropped by 1.5-2 but its an "absolute drop" even putting it on cruise @ 70 and it's not cracking 19mpg (observed or calculated)

 

IMO if you're going to mount these BFG's on a leveled truck may as well just step it up to the 275/65 size or 285/60 or whatever & go even bigger because the 275/60's are not much lighter may as well go big if you're going to take the hit.

 

While I was fully aware this would be the case & you may have seen me post in other threads adamantly opposed to going w/ heavy ass tires b/c of the corresponding performance & economy drops, besides all that you can simply feel that the truck is straining more across the board & it can't be good for it long term - and I have the 6.2

 

I should have taken my own advice

 

I did observe the following positives after adding these tires - #1 they ride smoother & quieter than the goodyear SRA's & they also absorb potholes & rough pavement much better - no surprise on that, but surprised w/ the smoother ride. #2 they hook up better in any condition @ any speed - partly due to the fact they sap power, but also because they're simply grippier.

 

#3 is the biggest suprise - I SWEAR these tires eliminated 90% of the "issues" people have w/ these GM transmissions/drivetrains - the constant locking/unlocking of the torque converter @ low/partial throttle, the eagerness to upshift too soon under the slightest throttle lift followed by a clunk & awkward down shift when you get back on it, combined w/ the constant variable valve timing & fluctuations between V5/V8 mode, pulled timing etc etc etc that all work together amounting to what many people think is a defect (in my opinion incorrectly as all auto trannys mated to big V8's in GM's stable seem to do this from my experience) - well that is all but eliminated w/ the tires & IMO its because the truck is under slightly more load @ all RPM's it simply forces the drivetrain/ECM/TCM to throw that mpg saving nonsense out the window pretty much right when you turn the key.....but that right there is the issue, adding 10-15 lbs+ per corner is a performance killer, & it is going to age the truck quicker in all facets - ball joints/steering rack/bushings/bearings etc. they'll all get abused more on a daily basis with these heavy tires, & while I appreciate the peace of mind knowing they'll grip better & prevent flats it isn't worth it to me.

​I'd rather have a slightly less aggressive P rated tire, keep the extra sidewall height for cushioning & ride height & save my truck's performance/drivetrain at the same time.

 

But I'll also go on record now and stick w/ my original tune - you guys out there running these tires & especially the much heavier ones are NUTS if you don't think its gonna kill your performance, mpg's, & wreak havoc on pretty much everything else that goes along w/ it like bushings/bearings etc. as I said. Running the heavy AT's on those 5.3 trucks ESPECIALLY ones w/ the 3.08's must be damn near depressing how gutless the trucks become, don't kid yourselves.

[Pearl2017]

I think your attributing an mpg loss mainly to wheel weight is not completely true. While the mass has an effect accelerating you seem to say the mileage was still off while also just cruising.

 

Nowhere did i see the pressures you run in the tires. Rolling resistance will go up as pressure drops so if you had the same pressure in the 2 different tires one may offer more rolling resistance. If you think about it a big heavy thick sidewalled tire has much more material flexing and generating friction/heat than a lighter thinner tire. The answer to getting the mpg's out of heavier tires is to run more pressure. When I had BFG's i ran 40-44psi and mileage was not a big issue and they also wore very evenly.

 

The other points you make about the trans and ride also logically fall in line with softer tire and higher rolling resistance. The trans searching is the control electronics doing a rough job of taking feedback and adjusting in a very difficult area of off throttle operation. added resistance/drag keeps it from entering that state so seems to work better.

 

My guess is if you put 45psi in those BFG's you would get back >1mpg and still not be close to BFG's max pressure. Then if you go offroad you get out and lower pressure like the jeep guys.

[crushNchowda]

I think your attributing an mpg loss mainly to wheel weight is not completely true. While the mass has an effect accelerating you seem to say the mileage was still off while also just cruising.

 

Nowhere did i see the pressures you run in the tires. Rolling resistance will go up as pressure drops so if you had the same pressure in the 2 different tires one may offer more rolling resistance. If you think about it a big heavy thick sidewalled tire has much more material flexing and generating friction/heat than a lighter thinner tire. The answer to getting the mpg's out of heavier tires is to run more pressure. When I had BFG's i ran 40-44psi and mileage was not a big issue and they also wore very evenly.

 

The other points you make about the trans and ride also logically fall in line with softer tire and higher rolling resistance. The trans searching is the control electronics doing a rough job of taking feedback and adjusting in a very difficult area of off throttle operation. added resistance/drag keeps it from entering that state so seems to work better.

 

My guess is if you put 45psi in those BFG's you would get back >1mpg and still not be close to BFG's max pressure. Then if you go offroad you get out and lower pressure like the jeep guys.

They're at 42 front 40 rear per recommendation from BFG customer service

 

The tires are too heavy for a 1/2 ton, even a 6.2 GM 1/2 ton....:this is my own fault I knew this to be true before I did just hoped I could offset it some w/ slightly lighter rims & a tune, still getting the tune but i can't stand driving the truck I paid nearly $60k for when I know I probably tossed 10%+ power & performance & mpg out the window on tires I spent $1200 on

 

Anyone telling themselves or anyone else that this isn't the case is simply lying to themselves. These tires belong on HD trucks or in the very least maybe put on headers and/or gears to compensate on a 1/2 ton.

 

It's a huge difference I felt immediately

[Sierra706]

They're at 42 front 40 rear per recommendation from BFG customer service

 

The tires are too heavy for a 1/2 ton, even a 6.2 GM 1/2 ton....:this is my own fault I knew this to be true before I did just hoped I could offset it some w/ slightly lighter rims & a tune, still getting the tune but i can't stand driving the truck I paid nearly $60k for when I know I probably tossed 10%+ power & performance & mpg out the window on tires I spent $1200 on

 

Anyone telling themselves or anyone else that this isn't the case is simply lying to themselves. These tires belong on HD trucks or in the very least maybe put on headers and/or gears to compensate on a 1/2 ton.

 

It's a huge difference I felt immediately

What were you running from the factory? I have 22s which weight about 90 pounds and can only imagine how much more sprightly the factory 18s feel.

 

The ridge grappler/method wheel combo I'm looking at will be either the same weight or 6 pounds lighter even with the LT tire, which I'm pretty pumped about.

 

 

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[Ezekiel2517]

I love the look and robustness of the BFGs. I use to run them on all my trucks. They wear poorly if you dont rotate religiously, but they last a long time if maintained.

 

But fear of the MPG hit is the main reason I went to the P-rated Nitto TGs. They are only marginally heavier than stock in 275/60/r20. In town my MPG difference is negligble. On highway it is slightly less, especially with winds, but I think it is due to the extra inch in diameter more than mass or tread. The tread is pretty quiet and tame for an AT.

[crushNchowda]

What were you running from the factory? I have 22s which weight about 90 pounds and can only imagine how much more sprightly the factory 18s feel.

The ridge grappler/method wheel combo I'm looking at will be either the same weight or 6 pounds lighter even with the LT tire, which I'm pretty pumped about.

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If you look at my original post you'll note that part of my rationale was that by mounting the BFG's on lighter rims pretty much brought the weight to within a lb or 2 of my friends setup w/ factory 22"s - My stock wheels were the 20" all terrains which are lighter than the 22"s for sure but heavier than my aftermarket 20"s that I mounted the BFG's on

[tanner709]

I disagree with the remark about the LTs making the transmission any smoother. My tranny is equally as bad, or worse with the heavier tire (note: they've always been upsized). I've ran the stock SR-A's in 265/65/18, BFG KO in 275/65/18, GY Duratrac in 275/65/18, Cooper Discoverer MTP 285/70/17, BFG KM2 255/80/17 and Hankook Dynapro ATM 265/65/18 for comparison.

 

The best AT tire I've used is the Duratrac, and the best MT tire is the BFG KM2, IMO.

 

On a similar note, what is the lightest QUALITY A/T tire? I would suspect KO2/Duratrac are high on the list.

What is the lightest M/T tire?

What is the lightest QUALITY wheel out there?

 

I hope you do see an actual difference, but, in order to properly do this test and receive factual results, you need the same road/weather/temp/weight/warmup conditions and you also need to be calibrated for size. Every one of the tires will measure differently even though they are all a "33inch" tire or "275/55/20"... unless you plan on running each tire for 6months or more, you will find very little difference in each. You couldn't provide me with enough data to prove the test results for me to ever be satisfied and make a confident decision on whether to buy this, or stay away from that. I think it's easier to accept you take a MPG hit with all of the above mentioned mods, tire size, weight, thread pattern/count, air dam removal, level, etc.

 

For me, in the end as long as I have confidence in the wheel and tire combo I'll pay time and time again.

[cortez24]

I'll be doing a similar comparison starting next week. I have about 6,000km on my completely stock truck, combined average mileage 14.2L/100km or 16.6USmpg. Hand calculated, includes a decent amount of hauling a 700lb load on the highway.

 

'14 all terrain, factory 20" AT wheels, factory ride height, air dam still there, 5.3L 3.42 gears. Crew cab SB.

 

Installed 2.5" RC level, air dam still installed - no notable change over 1,500km since install.

 

Installing toyo open country AT2 extremes on Monday - 305/55R20. Will run these for a few thousand KM and track mileage hand calculated accounting for change in speedo. Will then be adding a custom tune using my efi live flashscan to see if I can improve the performance with the change in tires and maybe gain back a little mpg. Will report back.

 

I fully expect to lose mileage, just curious to see how much.

 

Side note;

 

Toyo website rates these tires at 73lbs each, which is HEAVY I have them in my garage and they weigh 62lbs each. Go figure?!?!? I guess you can only trust manufacturer specs so much.

[crushNchowda]

I'll be doing a similar comparison starting next week. I have about 6,000km on my completely stock truck, combined average mileage 14.2L/100km or 16.6USmpg. Hand calculated, includes a decent amount of hauling a 700lb load on the highway.

'14 all terrain, factory 20" AT wheels, factory ride height, air dam still there, 5.3L 3.42 gears. Crew cab SB.

Installed 2.5" RC level, air dam still installed - no notable change over 1,500km since install.

Installing toyo open country AT2 extremes on Monday - 305/55R20. Will run these for a few thousand KM and track mileage hand calculated accounting for change in speedo. Will then be adding a custom tune using my efi live flashscan to see if I can improve the performance with the change in tires and maybe gain back a little mpg. Will report back.

I fully expect to lose mileage, just curious to see how much.

Side note;

Toyo website rates these tires at 73lbs each, which is HEAVY I have them in my garage and they weigh 62lbs each. Go figure?!?!? I guess you can only trust manufacturer specs so much.

You're going to regret it bro, unless you're totally show over "go"- I have a '15 6.2 w/ 8 speed now & the BFGs I'm running weigh 54 lbs on lighter than factory wheels totaling 90-91 lbs per corner according to my scale. My factory 20"s are wrapped in Michelin snow tires & they total about 79 lbs a corner- you're going to jump at least 15 more like 20 lbs a corner w/ your setup & you have a 5.3 6 speed truck.....it'll feel slower than the v6 trust me.

 

Fwiw I owned a 14 5.3 6 speed previously so I have some frame of reference

 

Oh & in case I didn't mention - 10,000 miles totally stock 16.4 mixed, 18,000 miles bilstein 5100s max height front, rear extra 1" block (2.25"), removed front air dam -16.2 mpg mixed, added the BFG's now I'm looking @ 14.5 mixed

 

You may be in the 13s

[Sierra706]

You're going to regret it bro, unless you're totally show over "go"- I have a '15 6.2 w/ 8 speed now & the BFGs I'm running weigh 54 lbs on lighter than factory wheels totaling 90-91 lbs per corner according to my scale. My factory 20"s are wrapped in Michelin snow tires & they total about 79 lbs a corner- you're going to jump at least 15 more like 20 lbs a corner w/ your setup & you have a 5.3 6 speed truck.....it'll feel slower than the v6 trust me.

 

Fwiw I owned a 14 5.3 6 speed previously so I have some frame of reference

 

Oh & in case I didn't mention - 10,000 miles totally stock 16.4 mixed, 18,000 miles bilstein 5100s max height front, rear extra 1" block (2.25"), removed front air dam -16.2 mpg mixed, added the BFG's now I'm looking @ 14.5 mixed

 

You may be in the 13s

Factory 22s at 90 pounds a corner give me 20-21 on the highway and depending on your definition of city driving around 15-16. Been getting 11 lately due to my commute being less than a mile and remote starting to warm up, but that's expected. I have the 5.3

 

 

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[Thornton]

I have the exact setup. Installed the bilstein 5100s at 4000 miles. added 275/60/20 Duratrac all terrains with 20 x 9 fuel coupler wheels to replace my factory 20 x 9 wheels. I still have the air dam installed

 

I now have 18000 miles and I average 14-15 mpg

 

 

[cortez24]

I Can tell you for sure I won't regret it, like I said I expect to lose mileage, and power. But tuning can greatly improve the lacking throttle response in these trucks and add a bit of power, I expect to still be worse mileage and around the same for power / throttle response after tuning.

 

I mean we're talking about tires that are roughly 2" larger in diameter and width with a bit more weight. It's not like I'm throwing 37s on the thing.

 

Like I said, posting for others reference, not to justify my purchase. I expect to sacrifice mileage and a little power for the sake of a truck that doesn't look like a grandpa-mobile in the summer months.

 

Will report back.

[Havvkeye]

I expect to sacrifice mileage and a little power for the sake of a truck that doesn't look like a grandpa-mobile in the summer months.

 

This was my rationale and I do not regret it one bit. Still has plenty of power for what I need and I have the 5.3 and heavier tires and rims.

[tanner709]

Do you guys all have the pedal flex fix done as well? Any engine mods/intake/exhaust etc? They are factors to consider as well

[crushNchowda]

Factory 22s at 90 pounds a corner give me 20-21 on the highway and depending on your definition of city driving around 15-16. Been getting 11 lately due to my commute being less than a mile and remote starting to warm up, but that's expected. I have the 5.3

 

 

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biggest advantage the factory 22" setup has over larger LT type tire setups that may weigh within a couple lbs of the factory bling is the 285/45r22 rubber these trucks come w/ from the plant have much lower rolling resistance so that helps w/ the mpg