Gas Mileage Difference Between 33 and 35-inch Tires – MPG vs SIZE
You can expect a 1 to 2 mpg difference when upgrading from 33” to 35“tires.
The larger diameter, width, and circumference add to the unsprung weight which has a direct effect on fuel economy, performance, gearing, and other drivetrain components.
- Big tire upgrades are all the rage and usually one of the first modifications 4WD truck owners have planned.
- How the bigger 35” tires will affect your gas mileage largely depends on the vehicle’s power output and a host of other variables.
- Remember, big tire upgrades, don’t only affect mpg but also affect braking, steering, handling, and performance.
What if you decide to make the switch from a 33” MT to a 35” AT?
MT tires are generally heavier due to the multiple plies, aggressive tread patterns, and deeper lugs.
Will moving to a 35” AT from a 33” MT have that much of an impact on gas mileage?
So we’ve established that you will see a decrease in MPG when switching to a bigger 35” MT tire.
- Users who have made the switch have reported a decrease of anything between 1-2mpg when cruising on the highway and 2-4mpg when driving in the city.
- Of course, the truck’s low-down torque and overall performance outputs play a major factor and figures will vary from vehicle to vehicle.
It’s not uncommon for Jeep Wrangler owners to fit 35” tires since they have SFA and plenty of options to improve wheel clearance.
Of course, re-gearing is key. Once you fit 35s it is recommended to go with either the 5.13 or 4.88 gears.
Even though frugal gas mileage shouldn’t be your main concern when driving a 4WD, many JK owners report a drop of between
Let’s see what to expect when fitting 35” tires to your truck
Difference Between 33″ And 35″ Tires Explained (Size/Height/Weight)
Yes, there are many important factors to consider when squeezing bigger tires on your truck.
Those factors include but are not limited to:
- Can The Drivetrain handle the weight?
- What’s the Minimum Suspension lift required?
- Does your truck have enough torque to accommodate the added unsprung weight?
- Articulation/Down travel – will you be going off-road?
- CV Angles (IFS) – will I need a diff-drop kit?
- Bump-stops – How will it affect wheel travel and articulation off-road?
Yes, sure, a larger tire will in most cases increase ground clearance and overall off-road performance provided your vehicle has enough torque to move those heavy tires and your drivetrain can accommodate the additional weight. Don’t forget the additional re-gearing of diffs.
Are the added complications that are part and parcel with big 35” tire upgrades really worth it.
What you need to be asking is the following:
- Are the added complications that are part and parcel with big 35” tire upgrades worth it?
- For example, most SFA trucks with 33s will be just as capable 99% of the time compared to those with 35s.
- Sure, there will always be a situation when the larger tire will outperform.
- The question then is, how often will this situation arise, and will the added hassle and major cost of fitting 35’s justify the number of times you’ll NEED it?
I guess it all depends on the level of wheeling you enjoy doing, or if the truck is a dedicated off-road rig and not being used as a daily driver.
The 35” tire will offer approximately 1” of clearance on the axle, but let’s look at some other factors you need to consider first.
These are just some of the factors that will be affected:
| Diff Strength | Refers to the strength and durability of the vehicle’s differential, which is a crucial component for distributing power to the wheels, especially in off-road or high-stress situations. |
| CV Joints (IFS) | Constant Velocity Joints used in Independent Front Suspension systems, enabling smooth power transmission to the front wheels while accommodating varying angles during steering. |
| Fender Clearance | The vertical distance between the top of the tire and the underside of the vehicle’s fender. Fender clearance is crucial to prevent rubbing or interference, especially in off-road conditions. |
| Bump-Stops | Rubber or foam components that limit suspension travel, preventing excessive compression and providing a cushioning effect during abrupt impacts or extreme suspension movements. |
| UCA Clearance | Upper Control Arm (UCA) clearance refers to the space between the upper control arm and other components, ensuring sufficient room for suspension travel without interference. |
| Wheel Offset/Backspacing | Wheel offset determines how far the wheel’s mounting surface is from its centerline, affecting the position of the tire concerning the fender. Backspacing is the distance from the wheel’s back edge to the mounting surface. |
| Gear Ratios | The ratio between the number of teeth on gears in a mechanical system, such as the transmission and differential. Different gear ratios influence the vehicle’s acceleration and top speed. |
| Speedometer Accuracy | The precision with which the vehicle’s speedometer displays the actual speed. It can be affected by factors like tire size, gear ratios, and modifications that impact the drivetrain. |
| Fuel Consumption | The amount of fuel a vehicle uses per unit of distance traveled. It’s a crucial factor in assessing the efficiency and cost-effectiveness of a vehicle’s engine and drivetrain. |
| Torque at the Wheels | The twisting force applied to the wheels by the engine. It’s a critical measure of a vehicle’s ability to move and is influenced by factors like engine power, gearing, and drivetrain efficiency. |
Read more about the differences between 33” and 35” tires here. (Size/weight/performance)
What User Say
USER #1
I would say maybe 1 mpg less. I had 285/70/17 (32.8) and went to 315/70/17 (34.4) and lost about 1 mpg.
The look of the bigger tires is well worth it in my opinion. Still get around 14.5 to 15.
https://www.f150forum.com/f4/33s-vs-35s-mpg-comparison-158993/
USER #2
For 2 years i got 285 miles to a 26 gallon tank on 295/70R18 Terra Grapplers.
I put my 275/70R18 Cooper LTZ’s back on my truck and now i’m back up to around 340 miles to a tank.
https://www.f150forum.com/f4/33s-vs-35s-mpg-comparison-158993/index2/
USER #3
With 35’s, I’d say you’re gonna drop 1-2 mpg around town assuming you also regear.
If you don’t regear, you’re gonna drop probably 2-4.
On the Hwy, I think you’ll drop probably similarly.
With 33’s, not really sure but somewhere shy of the above numbers but probably not by too much.
The key is to regear and get the power better delivered again to the tires and therefore you MPG will come back closer to normal (but not all the way back to factory/stock).
https://www.jk-forum.com/forums/modified-jk-tech-2/33-vs-35-gas-mileage-17131/
35” Tires And Your Drivetrain
The weight sits below the sprung suspension it, thus, falls part of the unsprung weight.
- This added weight has a direct effect on fuel economy, performance, gearing, and other drivetrain components.
- A 35″ tire is going to put additional strain on the drivetrain when hauling heavy loads,
- or when going up steep inclines and over obstacles off-road.
- Yes, it gives you the extra 1″ of clearance, however, there are drawbacks if you don’t upgrade the engine power to compensate.
Does 4WD Use More Gas?
4-wheel drive trucks use more gas since it has more drivetrain components and overall weight when compared to a 2WD of the same make and model.
4WDs have more drivetrain components such as an extra differential, transfer case, and an extra driveshaft, to name a few.
These major components all add to the weight, friction, and rotational mass which negatively affects fuel consumption.
When you add additional unsprung weight in the form of big 35” MT tires, you exacerbate the gas usage problem, thus decreasing your MPG.
Resources
- https://www.jk-forum.com/forums/modified-jk-tech-2/
- https://www.f150forum.com/f4/
- https://www.f150forum.com/
FINAL THOUGHTS
First, determine what the primary application for the upgrade is.
If improved aesthetics and a more aggressive stance are your goals or do you need maximum practicality combined with off-road ability while maintaining maximum articulation?
If you’re not taking it off-road anyway and the look doesn’t bother you, go low profile since a low rolling resistance helps somewhat.
In conclusion, the sheer weight, wind resistance, friction, and rolling resistance combined with the rotational mass of 4WD drivetrain components will always result in lower gas mileage no matter how you swing it.
