Tire size & spare questions
 

So a little different than the typical what tire should I get, I'll review those again as I get ready to buy. This question is about tire size.

So I finally got a full size rim (from a SportTrac) I'll use for a spare instead of the dougnut that comes with the FEH. It's currently wrapped in a 255/70/16 tire vs the 235/70 stock. Online calculator says it's 1" taller, reallife it looks more like 2. But I really liked the look of it on the Escape ;)
So the question is, what do different tire sizes mean, other then the obvious more or less rev/mi. I saw one place that talked about size & gear ratio & RPM's, but since we don't have a gear ratio how does that affect our vehicles? It said something like a smaller diamater = faster accel & higher rpm @ cruise, larger diamater = slower accel & lower RPM @ cruise.

So If I decide to get new tires & change size, what is the science behind the #'s? & how will the eCvt react? Obviously the spedo would be off too.

Part 2, spare. So of course now I have the doughnut, I guess it's the same diamater, if I recall when I inspected it a yr or 2 ago it was a 17", but just as tall as the 16's. Would you use that spare or a 255/70/16 as a spare until you could get all 5 to match several months down the road? I don't leave the city, in fact 95% of my driving is less then 10mi from home.
And part 2.5, The original rims & this 'spare' all have that plastic Ford cap in the center, I guess you have to pop those off to store it under the vehicle, since I have the U bolt on the tire lift?

Thanks!
Bryan

Happy New Year!

Re: Tire size & spare questions
 

Hi Bryan

I do not recommend changing your tire size and rims for a number of reasons. The rim you purchased may not center the same as the stock FEH rims - stick further out or in than the FEH rims. This will screw-up handling like being out of alignment. Using a spare tire that is 1" or 2" taller will also screw-up handling and the computer. If the wheel sensors are not showing near the same rotation and don't match the eCVT output shaft rotation, you will get a warning light as well as the ABS will not work correctly. Also, the FEH rims are special light weight rims and one heavier rim will cause a big decrease in MPG. Taller tires will generally be heavier also and reduce MPG.

My recommendation is stay with the stock rims and tires Ford Engineers designed the FEH with. An alternative LRR tire the same size and rating is fine, but compare the weight with the stock tires. Heavier tires or rims will always reduce MPG. Even replacing old worn tires with the same new tires will reduce MPG because the old tires have less rubber and are lighter. I just proved this issue with exchanging the worn tires and rims on my '05 FEH with my newer tires and heavier Limited rims on my '09 FEH. This brought my '09 tank MPG average to a record 63.4mpg with 13.6 gallons of E10 going 862.4 miles.

GaryG

Re: Tire size & spare questions
 

That's a significant difference that I'd be concerned about. My rig doesn't have TC so I really don't think it'd be a problem as far as the computer is concerned. Mine is an '06 though. As far as weight, meh. Put ONE heavier tire on and I bet the difference in fuel economy would be in the 10ths of a mpg if that.

If it were me I'd get a cheap used tire in the correct size to put on the spare. You can probably get the tire for $10 and get it mounted for next to nothing.

Yes, the center cap would have to come out in order to mount under your truck.

Re: Tire size & spare questions
 

You have no experience or knowledge on the subject which is clear in your post.

GaryG

Re: Tire size & spare questions
 

Thanks, I understand weight, well just about anything, is going to change mpg.

But how will the eCvt react to different size tires? If a taller tire = lower rpm at cruise on a std gear ratio vehicle, what will it do on ours?

Re: Tire size & spare questions
 

As mentioned here Ford does not recommend getting crazy with big tires for safety (i.e. rubbing) reasons. One of the minor headaches with changing rims is maintaining the tire pressure monitoring system, but that's another topic you can read about here. Personally I prefer narrower tires (also known as "pizza cutters" in the off-road world), as I'm currently running 225/75-16s. If you want to go wider, I would say a 245/70-16 tire is only .3" taller and would keep you out of trouble. The newer Escapes have 17" rims optional, and if you might be able to find a set of those take-offs for a reasonable price. When shopping new tires you want to make sure that the load rating is equal or greater to the stock tires' (104), to make sure the tires can handle your Escape's weight.
You are correct that a full size spare fits in the donut spare wheel well (just read your owner's manual for the tire changing procedure), but a 255 section tire will be a tight fit!

Re: Tire size & spare questions
 

First of all, you can change the diameter of all your tires but the manual states the PCM has to be reprogrammed for the change. This is so your speed will be calculated to match your speed and the other sensors. The PCM will flag a code if the sensors don't match.

The eCVT provides electric motor Assist to the engine when the engine load gets to 100% after the Warm-Up Strategy. It is very easy to know when you are at 100% engine load by watching the Assist Gauge needle or the SGII. As a hypermiler, I avoid the price you pay with battery drain using Assist. When you are draining the battery in Assist, you are no longer using MG1 to charge the battery. The Atkinson cycle engine has very little torque at low RPM so this causes Assist even at what most people would call slow acceleration.

Now, add more weight with taller heavier tires and you will increase the required torque to get them moving. This will raise the amount of Assist your engine will need to accelerate and maintain speed. Any gain from lower RPM with taller tires just will not happen with the FEH Atkinson engine and eCVT. Higher RPM and more Assist will be needed with heavier taller tires.

The example I used in my last post about changing my tires and rims made me aware of just how much tire weight can effect my mileage in both my FEH's. Even though I use little to no Assist in my '09, I jumped up 5 to 7mpg by trading my new Tours with the worn Tours on my '05 FEH. My wife and Son drive my '05 FEH and I can expect them to only average about 24mpg because they will not even try to hypermile. However, when I drove the '05 after the tire change, I seen a 3-4mpg drop from before the change hypermiling.

GaryG

Re: Tire size & spare questions
 

Hi Don

Are you seeing any kind of wear problems with the thinner tires on the FEH rims? The Tours are the same size as the Eco-Plus but are thinner, more of a car tread and weigh 29.4 new. The original Eco-Plus tires were 31 pounds new. Here is what I posted over 2 years ago:

"just got back from Goodyear who mounted the 2 Michelin Latitude Tours on the front of my '05 FEH. I brought a scale to weigh the '05 FEH Rim, so now we can compare the weights. The stock FEH Rim is 2.2 pounds lighter than my new '09 FEHL Rim which is 20.4 pounds. The standard FEH Rim weighs 18.2 pounds. If you add the new Eco Plus at 31 pounds, the total weigh is 49.2 pounds. If you replace the Eco Plus tires with the new Michelins, the standard FEH Rim and Michelin tire would weigh 47.6 pounds each. WoW! This is what my new tires and Rims weigh on the front of my '05 FEH now. The FEHL Rim and Michelin Latitude Tour tires weighed 49.8 pounds, which is .6 pounds more than the stock FEH rim and the Eco Plus. The folks that got the '09 FEH non Limited models have the 47.6 pound tire and Rim set-up."


If you do the math, I dropped 2.2 pounds with the standard FEH rims on my '09 FEH and I can only estimate that the 50% worn Tours dropped me down another ~5 pounds each from the new Tours. This dropped me down from 49.8 pounds with FEHL rims and new Tours to about 42.6 pounds each. That's down 7.2 pounds per tire and a total of 28.8 pounds less to get moving.


The 2011 Explorer Limited I ordered come with the Optional P255/50R20 A/S BSW 20" Hankook tires. If the stock tire and rim will fit where the doughnut is located, I will order a stock rim and tire for a spare and weigh them for comparison later like I did for the '09 and '05 FEH. Hopefully these tires and rims will still be a light weight set-up compared other tires and rims in there class.

GaryG

Re: Tire size & spare questions
 

Are you always an arrogant a-hole or is it just here? If you have facts to refute one thing in my post do it.

Re: Tire size & spare questions
 

Look J, you basically called me a liar in your first post. Now your calling me arrogant and a-hole because I think you have no experience or knowledge on the subject. The truth hurts sometimes but name calling is not permitted on this site.

I'm not going to call you names as that is a violation of the rules of this site which you choose to violate. When and if you come close to ever break World Records in MPG in the FEH, I'll consider you an expert and knowledgeable on the subject of tires and rim weight. I'm just trying to help people make good decisions from my experiences. Sorry, I thought your post was counter productive to my response.

GaryG

Re: Tire size & spare questions
 

Does everyone have to agree with you? If not, it means that they called you a liar? Hey, curb your ego.

Name calling may be against site rules but who's watching that the rules are being followed? I'd have to say that it's happened before. Any forum that allows a poll asking the members opinion on banning another member isn't being moderatored very well.

Re: Tire size & spare questions
 

I called you arrogant because rather than correct anything I said, you simply said I didn't know what I was talking about. Even if you were right, what was served by a post like that? If you were simply correcting my error that would have been one thing, but that isn't what you did. I will apologize for the other part. It was said for purposes of emphasis. I would have said it to your face, but this forum wasn't the place for it.

Remember where he was talking about having only the spare as a larger size? That's the part I addressed. Obviously he'd be only running that one wheel in larger size. I've had vehicles with TC and donut spares and they say to turn off TC when running the spare. This vehicle should be no different. I never said I advised running one odd-sized tire. Even your response to me didn't refute any of this.

Re: Tire size & spare questions
 

Bryan was talking about more than the spare tire and also how a taller tire would lower RPM's and increase MPG. One of your statements was completely wrong - "Put ONE heavier tire on and I bet the difference in fuel economy would be in the 10ths of a mpg if that." That statement is why I responded about your knowledge and experience on the subject.

Yes, I could have answered with a long reason why your statement was wrong but I had already just stated to Bryan about the effects of taller tires and MPG on the FEH. Your statement was simply your opinion that I was wrong and the effect would only be "in the 10ths of a mpg if that".

Since you apologized for your other statements after, I'll go a step further. I've learned a lot in the last 5 years about hypermiling and fine tuning the FEH for the best MPG possible. I've found that tires and rims are at the heart of putting the FEH to record MPG. If everything is perfectly tuned right with my FEH, I know it. If something is not tuned right, I find out what it is and correct the issue. This is a hobby of mine and I share the benefits of my experiences so others can have that knowledge if they want it. Sometimes I have a hard time explaining what works and what doesn't and have to rely on my mileage log as proof. This happened over a year ago when I found out that washing and waxing my FEH made it have more drag and gave me worst MPG. I'm sure there are still people on this board that will never believe that, but it's true.

Over the past 5 years I have seen the effects of having only one tire drop as little as 5 psi in pressure. My FEH gets out of tune every time and I feel it as well as see as much as 3 - 4mpg drop in my average MPG. The reason I know it is a low tire is because I locate it and add 5 psi and my MPG is back to normal. If all the tires were good after checking them, I know something else is out of tune. This happens and it's more often than not something I changed like waxing, overfilling the oil or changing tires.

GaryG

Re: Tire size & spare questions
 

My tires are narrower but they wear the same as stock from what I can tell. Even though they are much heavier than the stock (38 pounds), I'm finding that they only cost 1-2mpg for me from driving with the OEM Continentals. I suspect that Ford follows general styling trends and customer preference which have been driving up wheel and tire sizes for many years. This trend is not based on actual performance or mpg needs.

I see on the TireRack website that the have a 16x7" Enkei wheel that fits a FEH and weighs 13.8 pounds. I know there are other forged aluminum 16x7 rims (i.e. Volk Racing) that weigh less than 10 pounds if someone has deep pockets.

Gary, any idea what kind of mpg gain someone could expect to see with 10# wheels and lightweight LRR tires such as the new Kumho which weighs 25# in a 235/70-16 size?

Re: Tire size & spare questions
 

In theory, you should get much better mileage but that's not a certainty. Ford could have gone with a lighter rim and tires and they didn't for a reason. It may have affected regen, braking and traction. I try to fine tune a stock product rather than go aftermarket.

Back in the '70's I experimented with aftermarket stuff and always came back to stock parts that I fined tune. I slapped some huge rims and tires on the back of my Shelby for more traction which ruin my quarter mile time over the stock rims and tire size.

My stock '05 rims are the same as the stock '09 rims, but I got the optional Limited rims because I ordered the Limited package. The tire store that exchanged my wheels and tires was willing to bet me that one set of rims would not fit right. These guys sell aftermarket tires and rims everyday and were sure I would have problems because the rims were different on the newer '09 body style. I just smiled and said they will fix perfectly and they did.

The fact that you reduced the diameter of the stock tires and increased the stock weight, your real mileage maybe worse than you think. Those smaller tires increase your OD miles. Taller tires than the stock tires decrease your OD miles. When you divide the miles by the gallons you burned, it will never be right with your true MPG.

GaryG

Re: Tire size & spare questions
 

That's interesting, in a previous post you described how shaving weight off of your wheels and tires helped you gain mpg but now presented with an even lighter combination you aren't so sure it would work. Are you still sure about the mpg gain you attributed to lighter tires/wheels? :)
I would suspect the main reason Ford didn't go with lightweight forged rims is that they cost almost $500 each at the retail end.

I believe you misunderstood my previous posts, I have tires that are narrower in contact patch but about a quarter inch taller than the stock rims. I don't think it's difficult to calculate mpg if my speedo error is within 1%. I don't think any of us have calibrated speed/odo gages to ensure accuracy greater than 99%. For that reason I suspect my mpg calculations are just as good as they were with stock tires.

Re: Tire size & spare questions
 

Hi Don

You are mostly right here but are assuming to much of my statements. The '05 - '09 standard rims are lighter than the '09 Limited rims. The Eco-Plus 31 pound tires are heavier than the 29 pound Tours. My guess that the standard FEH rim with 50% worn Tours tires was met with a 63.4mpg tank. I can't say a lighter tire and rim will be better for MPG on the FEH, all I can say is what I got with my set-up. The set-up I'm using is a stock set-up on the '09 FEH.

GaryG

Re: Tire size & spare questions
 

Well, I'll put in my 2 cents. I had one of my factory tires pick up what looked like a piece of metal - unfixable. I took the opportunity to buy two new tires, and ordered the factory replacement spare rim, which I mounted with the remaining OEM tire. I much prefer having that full time spare back there, and I'm not fanatic about MPG - I just try and get the best I can...

Re: Tire size & spare questions
 

After driving on my '05 FEH temporary spare two weeks waiting to get an Eco-Plus tire from Ford, I did the same thing. Back then, I was one of the first '05 FEH owners to find out the tires were special order only from Ford.

Before delivery of my '09, I ordered a Limited rim and Tour for a full size spare and 2 Tours for my '05. At that time, I was already using my '05 full size spare and carried the temporary spare again. When I had destroyed the second Eco-Plus tire with chunk of medal the same place I did with the first one, I realized I was driving within a block of a medal recycling yard. The people driving those broken down trucks selling the medal were dropping medal all over the road. I changed that route right away.

Both my FEH's have complete sets of Tours and I use two old Eco-Plus tires on my full size spare rims. I still have both temporary spares in the garage as back-up also. I felt so much better having that full size spare for the second flat on my '05 FEH and I was able to wait 2 months for new Tours to become available back in July of '08. My '02 Explorer came with a full size spare but the 2011 on order will need one if it will fit.

GaryG

Re: Tire size & spare questions
 

OK, now that i've filtered through the flame war...

I'm going to be replacing the rubber on my 08 FEH within the next few months. I'll likely be replacing all 4 with Goodyear Forterra Tripletred's (I am a huge fan of the Tripletred series from Goodyear). I have the opportunity to pick up another FEH rim and i'd like to mount a 5th tire on that rim and use it as a spare. My question is this... will a full sized tire fit underneath in the spare wheel well? Obviously I need to pop off the blue oval but that's a non-issue.

Re: Tire size & spare questions
 

I am using a full size spare. I ordered the rim from the Ford dealer after I had to replace two of my OEM tires. It works fine, but I really disliked using the donut, which I used to get to Costco when buying my tires.

Re: Tire size & spare questions
 

Hi all, New to the site. I have an 06 Mercury Mariner. I realize this thread is for the FEH, but there was no mention of tire size on the MMH thread.

The MMH has 43K miles and I suspect original tires (Contitrac)

I need new tires before winter. My preference is Hankook DynaPro ATM. I have had great experience with several sets of these tires, but this is my first hybrid.

Any issues with going to a 225/75R16 tire?

They are ~ .1" bigger.
My goal is to get this aggressive tire (Amazing in the snow) but offset some of my lost MPG by going to a narrower tire.

The P225/75R16 DynaPro weigh 32.271 lbs (email from Hankook)
The P235/75R16 Contitrac weigh 32 lbs according to tire rack website

I suspect the new tire would be about 9-10mm narrower?

Thoughts?
Thanks,
Chris

Re: Tire size & spare questions
 

I have over 40K miles now on 225/75-16s and can report that there have been no negatives with respect to handling.
I suspect the main reason 235/70 tires are used for OEM are for styling preferences. Even 215s are OEM on a lot of older Escapes with 15" rims.

As you have noticed there are some significant cost savings with using the 225s and there is a wider selection. Since the Hankooks have a higher load rating (106) than OEM, can be inflated to 50psi, and weigh about the same as OEM, you will be safe and will likely not suffer any mpg loss. Plus everyone that gets rid of their OEM Continentals is happy they did.

Re: Tire size & spare questions
 

Thanks for the reply.
Many 225/75R16 are L/T tires, that adds about 10 lbs, but Hankook makes these in P rated tires which is good for me. 50K mile rated and carry the Sever Service Emblem (snow flake) These tires are Awesome!

Found them $25 cheaper online. Discount Tire matches online tire stores but they always throw in the shipping charges, but I always contest the no taxes, so they usually give me the online price. Everything's Negotiable!