225/70/15 vs 235/75/15

[joshkeller]

Hey guys, 2001 2.3 5 speed with 3.73 rear end. I bought the truck for beating around back and forth to work and hunting camp and occasionally towing my small boat or 4 wheeler (both under 1,000 lbs including trailer).

I want to maintain good gas mileage. That said, the stock 225/70/15 tire market leaves a bit to be desired. Has anyone stepped up to 235 75 15? I know it's a 5.4% difference in tire height. Will gas mileage be killed? Will the extra tire height/weight make the truck a slow accelerating turd?

 

[sgtsandman]

Going to a bigger tire will slow it down a bit but it shouldn't be horrible.

What's wrong with the 225's that you want to move away from them? Some tire brands are better than others and tread pattern can make a huge difference. So, it might not be a size problem but a design one.

Either way, we're happy to help you out where we can.

 

[pjtoledo]

my 2005 is the same as yours. with about 370,000 miles on it I've had several sizes of tires.
stock was 225 70 15 on 6" steel wheels.
I do strictly road use so 235 75 15 ATs were ok, very little difference.
the 245 70 16 was a bit too much, definitely slowed it down and a noticeable decrease in braking.
currently running 235 70 15, great size for my needs. factory style 15x7 aluminum wheels.
another size I had was 225 70 16 dedicated winter tires, they were fine.

since you're in West Virginia I'll assume that you stay off the flat 'n level roads and would appreciate the extra
braking & climbing power of the shorter tires. YMMV

 

[joshkeller]

Nothing wrong with 225/70/15. The truck came with 235/75/15 - two all seasons on the front and two winter LT rated tires on the back. I'd like to get new rubber all around - just debating staying with the 235s vs going to stock size. A local guy has a set of 235/75/15 all terrains on wheels that I wouldn't mind getting, but if I'm going to lose 2+ mpg over the stock size, I'd rather just replace what i have with new highway 225's.

This isn't my primary truck, but a beater that I want to be as efficient as possible.

 

[sgtsandman]

Nothing wrong with 225/70/15. The truck came with 235/75/15 - two all seasons on the front and two winter LT rated tires on the back. I'd like to get new rubber all around - just debating staying with the 235s vs going to stock size. A local guy has a set of 235/75/15 all terrains on wheels that I wouldn't mind getting, but if I'm going to lose 2+ mpg over the stock size, I'd rather just replace what i have with new highway 225's.

This isn't my primary truck, but a beater that I want to be as efficient as possible.

Any time you go bigger, with an exception here and there, is going to ding the fuel mileage but not by a huge amount with the tire sizes you are dealing with.

Now,if you are going from an all season tire to an AT, the hit is going to be a little bit more due to the rolling resistance increasing.

As a guess, the hit is going to be about 1-2 mpg. I lost about 3 switching from an all season to and AT but I also stepped up from a 29" tire (235/75R15) to a 31" tire.

 

[bhgl]

@joshkeller I just did all this research myself recently for my 3.0 Auto truck with a 4.10 rear end. I went with a 205/70R16 touring/highway all season. I've seen better coasting, and slight improvements in fuel economy when compared to a just barely wider winter tire setup.

Upping the tire height diameter CAN sometimes improve mileage if it puts your RPMs in a better range at cruising speed. You'll have to do some math to figure out if upsizing the tire diameter is worth it for you. It will make your truck accelerate even slower however.

The best choice for fuel economy (in my opinion):

Overall, the best benefit you'll see will be from reducing the tire's width, and selecting a tread that's lowing rolling resistance. If you can find affordable 16 wheels that are 6.5 inches wide or lower, then I would recommend purchasing 195/75r16 tires. These are found on commercial vans, and typically have a 105/107 Load Index rating meaning you can load up your truck, tow, and be in a safe range, while still having the thinnest possible tire. These tires are very thin a 7.7 inches wide when compared to the stock 8.8 inches from a 225/70r15, but still support a lot of weight.

The other best thing you can do in regards to wheels and tires is to go for a lighter wheel, alloys will save you some weight over steelies and help with towing, overall fuel efficiency, and performance. Since you do haul, even though its not the heaviest, make sure you buy quality alloy wheels, or OEM alloys.

My recommendation for you:

In your situation and with your current 15inch wheels, I would recommend either sticking with 225/70r15s, or down sizing to either 205/75r15, or 215/70r15. You will get just over 1% reduction in tire height on both, and a reduction of 0.8, or 0.4 inches in width respectively.

Overall, you're not going to see a remarkable improvement in fuel economy, but you may see some, if you need new tires then I'd recommend going smaller, if you don't need new tires, save yourself the money to buy gas.

EDIT: Read your other posts a bit more closely, ALL of the tires I mentioned should give you some sort of fuel economy benefit compared to those 235/75r15 tires you have.

Since you're looking to get new tires, if you also want to buy wheels, then i'd go for the 195s, if you want to keep your existing wheels, then 205/75r15 is my recommendation, but you'll see some improvement by just getting new 225s as well, they're also a lot more common.

 

[joshkeller]

I also found a set of 215/70/15 locally so that also works. Will a highway style tire be suitable for gravel roads? I don't off road, but I do have a gravel road to get to my hunting lease. I'm not worried about getting stuck, but I don't want punctures.

I am totally fine with the acceleration I get now with the 235/75/15, but I haven't hooked up the trailer or driven it with stock size tires to compare.

 

[racsan]

my ‘94 2wd 2.3 ran 4.10’s and my experience with 225/70 vs 235/75’s is that when empty, just driving back & forth to work was very little difference. speedometer was most accurate with the 235/75’s- usually got 21 at best. What was noticeable was towing & acceleration. with the 225’s it did get up to speed quicker and did reasonably well towing. With the 235’s it would go a little faster but took a lot longer to max out, and didnt like towing much more than a empty trailer. My transmission was the M5OD manual overdrive.

 

[joshkeller]

I know all too well about the 1994 with 2.3. That was my.previous beater before getting this 2001. That 2.3 lima with 3.08 gears was AWFUL. Witj 215/70/15 tires, It pulled my boat and 4 wheeler locally on flat ground surprisingly. Just driving back and forth to work and beating around town it struggled to get 18mpg due to the awful gearing. This 2.3 duratec is noticably stronger.

That said, I will only be towing short distances with this ranger unless I pull the 4 wheeler to hunting camp which is 140 miles away. My primary vehicle is a 2018 ram with a hemi, so it will do all the heavy work.

my ‘94 2wd 2.3 ran 4.10’s and my experience with 225/70 vs 235/75’s is that when empty, just driving back & forth to work was very little difference. speedometer was most accurate with the 235/75’s- usually got 21 at best. What was noticeable was towing & acceleration. with the 225’s it did get up to speed quicker and did reasonably well towing. With the 235’s it would go a little faster but took a lot longer to max out, and didnt like towing much more than a empty trailer. My transmission was the M5OD manual overdrive.

 

[bhgl]

I know all too well about the 1994 with 2.3. That was my.previous beater before getting this 2001. That 2.3 lima with 3.08 gears was AWFUL. Witj 215/70/15 tires, It pulled my boat and 4 wheeler locally on flat ground surprisingly. Just driving back and forth to work and beating around town it struggled to get 18mpg due to the awful gearing. This 2.3 duratec is noticably stronger.

That said, I will only be towing short distances with this ranger unless I pull the 4 wheeler to hunting camp which is 140 miles away. My primary vehicle is a 2018 ram with a hemi, so it will do all the heavy work.

If it's hard packed stuff you'll be just fine with a regular all season tire. If you can do that road in just 2WD you'll be more than fine. I've driven standard all season tires up and down gravel roads every day for 3 years and never had an issue, if you've got loose gravel, medium size rocks, or a lot of soft sand then getting an all terrain is the worst idea, but your mileage is gonna suck. I'd say get the 215s that are local and call it a day.

 

[rubydist]

The 2.3L is a dog to begin with. I would not make it 5% more of a dog by putting on taller tires.

 

[joshkeller]

Went with the 215 70 15. Drove 150 miles on the tank with the 235 75 15 and got 26 mpg.

The smaller tires definitely ride nicer than the old ones. Acceleration isn't much different, but the truck is able to hold speed much better at 70+ in 5th gear at approx 2800 rpm vs 2550.

 

[joshkeller]

For a small sample size update -

I drove 150 miles on the 235/75/15 and hand calculated 26 mpg. That was verifying the true mileage driven by gps.

Drove 152 miles this weekend (again using GPS to verify miles). Lots of 55 mph country roads and got 30.6 mpg.

Much smoother ride, better acceleration, and definitely able to cruise in 5th gear at a much lower speed than the bigger tires. Overall I'm very happy with the change. Bought the new wheels and tires for $200 and sold the old wheels and tires for $100. It won't take long to recoup my $100 investment in gas savings.

 

[bhgl]

For a small sample size update -

I drove 150 miles on the 235/75/15 and hand calculated 26 mpg. That was verifying the true mileage driven by gps.

Drove 152 miles this weekend (again using GPS to verify miles). Lots of 55 mph country roads and got 30.6 mpg.

Much smoother ride, better acceleration, and definitely able to cruise in 5th gear at a much lower speed than the bigger tires. Overall I'm very happy with the change. Bought the new wheels and tires for $200 and sold the old wheels and tires for $100. It won't take long to recoup my $100 investment in gas savings.

Congrats on breaking the 30MpG barrier! I'm a big advocate for downsizing tires on these trucks, with a 4MpG improvment you'll pay yourself back in a month or less depending on how much driving you're doing.

 

[scotts90ranger]

In my experience the tread design makes a much bigger difference in mpg than tire size. My '97 has 4.10's and had some random tires on it when I got it, somewhere around 27" tall, drove fine, rpm's a bit high for my tastes but they were old and not very round and all season tread or all terrains... those got 19-21mpg. Then in an attempt to lower the engine speed I got some 235 75 15 tires, all season as well, those got me 22mpg, then I found some 225 70 15's in a car tread and those jumped the mileage to 23-25mpg depending on season (it's got some temperature issues where it doesn't warm up in the winter which is a gas suck...). All tire sizes the odometer differences were verified and accounted for. I didn't like how much I had to shift with the 235's so I went down, much better...