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Pretty truck. How big a block? I just measured mine again today and it’s basically level when I tow my boat. I’d hate to raise the front then have it squat in the back end when the boat is hooked up. If I want bigger tires I’ll probably have to raise the front and back. Thinking Bilsteins and a block on the rear.
You guys with the 33-34” wheels, did you lose much in mpg after the change? I have a stock 32.1” with a 3.55 rear and 5.0 L, wondering what I’ll get if I jump to 285/70/18? Think I asked this before but might be some new blood on here since then. Wish they had that size in something besides E rating.
To be blunt, since we have answered several of your (valid) questions, it's a truck. You might be less concerned with fuel economy... if you are more concerned with great fuel economy for a +5000 lb vehicle, then don't modify it to fit bigger, heavier tires.
Simple.
You may see a +/- 2 MPG drop from the truck's stock configuration. A re-gear from your 3.55:1 to a 4.10/4.11:1 will bring some of that back, MAYBE, depending on your driving style.
I haven't done my axle gearing change, yet, but it's on the list. That, and an Eaton Detroit Truetrac helical-gear limited-slip differential.
I gotz a 4:11 in da Z28, but I don't expect much in the way of mileage out of it.
I woudn't, either!
But, for the sake of some clarification:
Does it have a double- or triple-overdrive transmission? Yeah, baby, yeah!
Does the car also have wheels/tires 30 lbs heavier than what the OEM had on it? Are they 3" larger, changing the effective final drive to Mt. Everest? See!
A re-gear CAN help. But only under the above circumstances, and, too, remembering that no matter what we ain't overridin' the lawrz o' physics.
To be blunt, since we have answered several of your (valid) questions, it's a truck. You might be less concerned with fuel economy... if you are more concerned with great fuel economy for a +5000 lb vehicle, then don't modify it to fit bigger, heavier tires.
Simple.
You may see a +/- 2 MPG drop from the truck's stock configuration. A re-gear from your 3.55:1 to a 4.10/4.11:1 will bring some of that back, MAYBE, depending on your driving style.
I haven't done my axle gearing change, yet, but it's on the list. That, and an Eaton Detroit Truetrac helical-gear limited-slip differential.
Actually, I like blunt. I do appreciate you and everyone having patience with my many questions. All the replies and suggestions have been very helpful. I doubt I’ll go so far as to change the gearing, and 2-3 mpg isn’t bad. I guess I’m torn. I want a more aggressive look without messing up what I’ve had the last 100k miles, ride and mpg wise. I’ll get it figured out. Thanks again.
Does it have a double- or triple-overdrive transmission? Yeah, baby, yeah!
Does the car also have wheels/tires 30 lbs heavier than what the OEM had on it? Are they 3" larger, changing the effective final drive to Mt. Everest? See!
A re-gear CAN help. But only under the above circumstances, and, too, remembering that no matter what we ain't overridin' the lawrz o' physics.
4-spd. auto OD
Tires almost an inch taller, 9lbs heavier, and a lot wider.
^ ^ ^ I sure do like that project! And I expect your flawless job on that carburetor rebuild to be rewarding, too.
[we get to see Phil's fastidious, impeccable craftsmanship in a secret thread - hee]
Originally Posted by shorerunner
Actually, I like blunt. I do appreciate you and everyone having patience with my many questions. All the replies and suggestions have been very helpful. I doubt I’ll go so far as to change the gearing, and 2-3 mpg isn’t bad. I guess I’m torn. I want a more aggressive look without messing up what I’ve had the last 100k miles, ride and mpg wise. I’ll get it figured out. Thanks again.
You could if all you'd like is a more-aggressive appearance find one of the lightest P-Metric you can find (rather than an LT), choose a wheel also for it's lighter weight and come in at under 70 lbs total each wheel/tire (17 X 8.5 Motegi Trailite and P285/70-17 Firestone A/T2)
... and some A/T tires can have a decent appearance but also have far less rolling resistance than others. These things go a long way to minimize the hit on your fuel economy. Ask me how I know.
I went from this:
To this:
...and suffer an additional 1.5 MPG loss across the board from the first 1.5 MPG hit going from the OEM tire size and super-light weight.
I don't like the mpg loss but I expected it. I still don't like it, but now I have a tire and wheel better suited to tight turning (no rubbing), better off-highway traction and a more-durable tire for when I'm 50 miles from pavement. Everything we do that affects unsprung weight and effective final drive gear ratios matters, and everything is a tradeoff.
shorerunner, I just looked and a 285/70-18 is not available in the Firestone pictured but I have started a chat convo w/ them (tirerack) with this question:
Looking for a 285/70-18 P-Metric all-terrain for it's lighter weight than an LT, and for a '21 F150. Can you help? Thank you in advance.
Thank you. No, sorry. That is a pretty uncommon size (also bigger than we can confirm will fit). We offer just a handful of tire options in that size and they are all LT metric.
Their reply.
They (TireRack) do not always stock, even offer, every size available so I just checked the official Firestone website to see if the Destination A/T2 is even made in a 285/70-18 (and as a P-Metric, too), and, no luck.
You could look and see if BFG offers the ubiquitous and worthy KO2 in that LT285/70-18 but in a C Load Range (rather than an E)...
