Home Forums Gear Hunting Trucks and Four-Wheel Drives Going from 33" to 35" tires ?

I am thinking of going from a 33" tire to a 35" tire on my RAM 3500 diesel. I imagine I'll get worse mileage, but what about the RAM being able to handle the extra weight. Anyone who has done this has the front end held up? Anything else I should be away of should I go this route?

Something to also be aware of is that not all 35" tires are created equal with regards to actual size and weight. I've had a 33" Firestone and a 35" Dick Cepek that were almost the same actual size, with the Dick Cepek being the same weight.

I would think the front axles would handle the additional weight just fine. My concern would be that you have the 3500 diesel so you can tow and when you put larger tires on the truck your effective gear ratio becomes higher (lower numerically) and that take power away form the truck.

Good point. Some sites do show tires actual size so that may help.

I suppose it would take a little away. It does have plenty right now. I thought I would be towing a lot more with it, but that hasn't panned out. A 28ft bumper pull camp trailer and hay once a year has been about it.

The circumference of a 35 is 6% more than a 33, assuming those are the actual diameters. You'll be traveling 6% faster at any rpm and have 6% less power.

Something else to consider, will the 35's clear everything around them when turning tight?

From what I have seen and read 35 fit the 2018 Rams with no problems.

I could live with that

How would the tire chain clearance be?

Going to a 2" taller tire only adds 1" to your clearance. Is that worth the cost?

Based on all the ‘plus sizing’ I’ve done, I’m guessing they will probably fit but be real close to rubbing, chains will be a no go (but may be a no go with your current size already), and you probably will not notice a major loss of power.

With the Kelly TSRs I have had on them I have yet to need chains. There is quite a bit of room in the wheel well, but it would be something to check.

Thanks. That is helpful

If you have to change differential gearing, that's a LOT of money to gain an inch or two.

On my 2011 Duramax I went from a 31.6” stock size to a 34” and didn’t notice a loss of power or towing ability towing a load similar to yours. I never towed super heavy, but I drug the trailer across the Rockies several times. This was with a 3.73. Remember, the manufacturer puts out different sized tires on the same truck/transmission/rear ended. They can vary by an inch or 2.

On another gas 3/4 ton truck I went from a 31.6” to a 32.7”. I haven’t driven it enough (it’s my daughters truck) to tell, but I’m guessing I won’t notice the difference and mileage may improve (it has 4.10 rear end).

I had an 89 with a 350 that was a high geared 3 speed to begin with. I can’t remember the tire size but I did notice a loss of power when sizing up a few inches. But it had less power and worse gearing to begin with.

This was going to be my next question to find out if people had really felt much difference in actual performance with the power it has.

On my RAM I have 800 torque and 370 HP so a little loss won't be that noticeable I feel for what I do with it. It has 3.42 gearing and would go to 3.23 with the 35s.

Pretty tall rear end. How many forward gears in the transmission? It’s really the final drive ratio that matters. With a 5 or 6 speed you have more options when it comes to keeping the motor where it needs to be. My old 3 speed was a dog in third primarily because the jump from 2 to 3 was so much that it fell on its face until it got up and running.

It is a 6 speed.

You will lose some performance for sure, but may not really be noticeable.
If it's slow to get off the line now, it will be even slower. If it has to downshift now to get up hills, it will have to sooner.
Everyone's different in what they consider adequate performance. Some of these mall crawling jeeps couldn't get out of their own shadow, but most of the drivers don't care. My guess is it will do just fine.

Thanks. Getting going hasn't been a problem and even my wife likes driving it when she passes people since it takes off so well. Last year I had to stop for construction at a steep grade pulling the camper. When i took off it just pulled with easy increasing speed up the hill.

If you like an accurate speedometer, you'll need to change the gear... maybe. I think most of them now are computerized so you need a shop to reset it.

If you want 35" tires get them, you won't notice enough difference to matter.

There are programs that tell a person what their speed is with different tires so I am ok with it.

Thanks

A dealership can reset your speedo, or you can do it yourself with a tuner. It is really easy to do.

I also doubt you will notice any performance difference. You might notice more squish in the sidewalls with taller tires, but that varies as much by tire as it does by height.

Thanks, I thought about getting a tuner once the warranty is warn off.

Your Speedo and Odo will both be off by 6%. So an indicated 25 mph would be about 26.5 actual. An indicated 60 would be 63.6, and an indicated 75 would be 79.5. You can always use a GPS to check. Most factory speedos read pretty close to actual or a bit high, so your difference may be a bit less.

ETA: I now see Rock Chuck said the same thing earlier with fewer words.

Right. We have a 2011 GMC that had 31's on new and now has 33". At 70 it shows 66. I didn't know this when I bought it and was surprised I was passing everyone on the freeway. Legal limit is 80 so I was going ~85. My wife was driving our Camaro following me home and had to get close to 100 (She enjoys the Camaro) to catch me since I left a bit before her and let me know what my speed was. Good thing I didn't catch the attention of the HP. Her too.

You might not need to spend the big money on a tuner. There are cheaper routes to electronically adjust for taller tires. It also depends on the year of your Dodge. Newer trucks can have their shift points thrown off by not having accurate speed due to taller tires.

What are the cheaper routes?

I don’t know about Dodge but with Ford you can use the Forscan app and plug your laptop into your truck to adjust the speedo among other things.

Does ford really have app called "forscan"? Is it part of the power-stroking suite?

yes, they do.

After doing some research I found that a lot of people were complaining about the difficulty of uninstalling forscan. Apparently it can be quite painful to remove.

Honda makes another app that can remove forscan. It's called civicsision. I guess that's best done when the vehicle is brand new.

LOL. Great stuff, I think a lot of guys may not have caught it!

I drive a 2012 Ram 2500, Cummins, 6 spd auto (68RFE), 3.73 gears. I am currently running 315/70/18 Toyo M/T's. From 33 to 35 to these (36), I've noticed very little change in anything other than the speedometer. My truck is deleted and has mild tuning. I've pulled 10K pounds with it with no issue. Only thing I do is to run it in Tow/Haul when I'm running around the mountains of Tennessee and North Carolina, just to help the tranny not shift so much. Can't speak to the chain issue, but 35's shouldn't be a problem for clearance on their own.

Thanks for the info

Or a GPS.

Or just reprogram the computer so you can use the speedometer as intended. Keeps the odometer accurate too.

Personally with 35s I would be looking at new gears, probably 4.10 at minimum, which is where I think gearing should actually start in all trucks and a reprogram. Just what I have come to prefer if going with larger tires.

If more than a 5 speed auto I wouldn't have an issue with 4.33 or lower as long as you aren't going to be at too high of RPM at say 80sh MPH.

35s drop fuel mileage but you have enough truck to be fine on the power side

I'm not following this. FORScan does not install 'on' the vehicle. It installs on to your computer, then you use an OBDII adapter to connect it to the OBDII port in the vehicle. You select the module you want to modify, then make the changes and save them. Then you unplug the adapter. I've used it to activate a factory brake controller and turn off the door/ignition chimes, and a few other changes. Pretty easy to use once you get the hang of it.

Hahahahahahaha!! :-)

Set the hook!!!

I have 35s on my 3500 and will go back to 33s when i need new tires. I want the extra bed rail clearance when pulling the 5r and i am hoping that the MPG will increase both loaded and empty. I am fairly easy on the skinny pedal and get 18-19 on the hiway. I would like to be 20ish like my old 12 vlv. Most all aftermarket tranny builders will not warranty a build if the tire size is over 35".

Most all aftermarket tranny builders will not warranty a build if the tire size is over 35".

With at least one manufacturer putting 37s on a vehicle, (Ford Raptor) do you feel this will continue. For the record I have no plans to go to 37s.

I have no idea about gas rigs, a Ford Raptor interests me not at all, mainly because it is a Ford. One of the main reasons for the disclaimer is the way the D2 engine builds torque. If engine RPM drives the trans pump there is only so much builders can do to increase trans line pressure at low RPMs where a D2 engine makes the most torque. If peak torque comes in at say 1600 RPM and peaks at 2400 RPM that is not alot of fluid movement in comparison to a gasser that has max torque at 4000 RPM. So much easier to let the smoke out of trans parts behind a D2 engine...have done it several times. Little tweak for more power kills the factory trans, buy an aftermarket and think i will never be over the HP rating of this trans. Another little tweak such as a programmer, turbo or injectors because (you think) the trans can hold it, right? Wrong. It can and will for a while then it lets go and you are shopping again. Soon you have spent 22K on 3 different transmissions to get a trans rated at 850 HP that you should have bought the first time. I think if you were to swap gears with the taller tires you will do yourself a favor. if you have 3.42s going to 4.10s or 4.30s would be ideal.

Sorry SP. I was just being a dick.

I take back everything I said. I think that people ofall religions should use this application. Forscan isn't just for Gentiles anymore.

OP, sorry for sidetracking your thread with dick jokes, but a cheap laugh is.... still a laugh.

The equivalent Ram app to the unfortunately named Forscan is Alpha OBD. You'll need an obd2 interface. I got the obdlink mx+, but there are many. That one can Bluetooth your phone to your truck and let you check codes and adjust settings.

There are probably more than a few apps that can perform this task, and AlphaODB is probably the most expensive at $49. But I'm betting there are a few options that you will want to change that will be easy to do with it. For example, keeping the fog lights on with high beams and turning off that stupid seatbelt chime. (you can do that without an app, but just an example of one of the settings that you can mess with)

2014 Cummins with 35s and leveling kit. Speedo is still on. Go for it.