Tyre question - appearance of tyre/sidewall/etc.

Hi folks,

Have a (very silly, no doubt) question with regards to the world of tyres. I'm not really that clued into the different varieties or their functions or purpose, etc.


Pretty much, I picked up a Toyota Rav4 a couple of weeks back and was told I'd need two new front tyres. So I finally am getting a chance to get around to doing it today.

So one thing I notice from being around the car is that the two tyres on the front are different to the two tyres on the back. I don't think it matters or such, but here are the tyres.


Front (215/70/16):



Back (215/65/16):



Car itself:




Anyway,

The gist of it is that the back tyres are better looking than the front ones (in my opinion). It's a tad more aggressive looking (Which I like). So I'd like to try to get something a bit similar if possible. I also notice that the back tyres, for whatever reason, seem to take better to those 'back to black' type of sprays, etc. that are out there (the back tyres go a nice shiny black, but the front ones go back to a dull grey fairly swiftly).


I also notice that, for whatever reason, the back tyres seem to be a little bit smaller than the front ones (215/70/16 VS 215/65/16). Despite the sizes not being much apart, visually you can notice that the sizes are different.



So I was wondering if there was anyone out there who can assist regarding tyre appearance? I know there are different types of tyres (winter, summer, etc.) so I don't know if it's just a case that the front tyres are summer and the rear ones are winter or whatever the case may be.

Also, can I get 'taller' tyres (bigger sidewall)? If so, would that make the overall driving experience a bit smoother/more comfortable (for crappy road surfaces, etc).

Never really had to do anything with tyres in the past, so a bit lost to be honest. I know these questions probably belong on a 'Idiot's Guide To' type of forum but sure if I never ask, I never know.


A place i visited today briefly reckoned they'd get me 2 'GT Radial' tyres fitted for €105 each (€210). Not sure if that's good or bad. They said they'd need to order them in as they don't have it in stock. Not sure if that's good or bad pricing but no idea what a 'GT Radial' means or is (brand name I assume).


Cheers to anyone able to make sense of this disastrously written thread. Haha.

pete4130

With 4WD's its more important to have 4 tyres that match and are the same size.
Your rear tyres are smaller than the fronts and it is an issue of sorts.
All tyres are 215mm wide. The rear tyres are 65's (meaning they are 65% high from the rim compared to the width of the tyre). Your front tyres are 70's meaning they are 70% high compared to the width.

This means your fronts and rears have different circumferences...meaning 1 revolution of your front wheels ISN'T the same as the rears. This can put undue pressue on the drive train of a 4WD, lead to uneven tyre wear and other drivetrain issues. Again, it all depends on the type of AWD/4WD system your car runs. As you're probably in 2WD/RWD most of the time it may not be a big issue.

Find out what the stock tyre is for your car. If the tyres are too small it increases your RPM to maintain a certain speed/increases fuel consumption and puts the speedo out (tells you that you are going faster than you actually are). The opposite will be in effect if the tyres are too big. You can live with a 3% difference in tyre size before its really any sort of issue.

The tread pattern & depth on the tyres is different too. This can affect the circumference of the tyres as well. Thats why it is recommended that you have all 4 tyres the same on a vehicle, moreso a 4WD. Basically your front wheels are revolving more slowly than your rear wheels and wheel/tyre size will affect your gearing.

The higher the sidewall, the more comfortable the ride but the it reduces handling. The more aggressive the tread (as in deep, AT/All Terrain style tread) the better it will be for off roading (usually designed for 60% road, 40% off road). More aggressive tread means higher noise, less grip and higher fuel consumption. For Ireland, HT (Highway Terrain, 90% inroad use, 10% off road use) is good enough. More quiet, better fuel economy.
You've got 16 inch rims on so 65 or 70 profile tyres are fine for anything you'll encounter in Ireland.

The GT Radial is just a brand/style of tyre. It's a well known, recommended brand and probably comes in different guises (HT/AT etc...)

Stop giving a crap what tyres look better or what tyres take back to black spray better and worry about their performance.

This is all the extra cost/maintenance that comes with an AWD/4WD system that you were informed about.

Cost of the tyres isn't too bad either.

mathepac

First port of call is the Owner's Manual to see what size tyre Toyota fitted originally and put four of them on the car. The fronts look bald.

I would suggest you steer clear of knobbly off-road tyres unless you will be doing knobbly off-road driving. They may look macho but they'll wear out quicker on regular roads, make more noise and will be less than good in the wet on tarmac. . Having said that, put enough back to black on any tyre and if it gets into the treads, you'll be figure skating for Ireland in no time.

Put Toyota recommended tyre sizes on, make sure they are a quality brand and matched to the conditions you will be using them in. Price / looks should be way down the list of criteria especially if you are transporting family.

Cheers Pete. Never really knew you knew about cars and such.

Firstly it's probably best to point out that, whilst there is a four wheel drive Rav4, my one isn't. It's front wheel. Four wheel would be wasted on me, so I didn't bother with it. It also means buying a Diesel, and i wanted to stick to petrol as, from reading on here, it'd be better for my driving style (lots of start stop traffic and not that much mileage in general).

From what I can see, the standard size for the RAV is 215/70/16 (which means that the front tyres, that i'll be changing, are the right size, and the rear ones, that I'm keeping, are the wrong size, being 65 instead of 70).


I'd imagine that fuel consumption would be negligible in moving to slightly larger tyre? Would only really make a big difference if I put a gigantic tyre on there (although I don't know how big i can practically go). Ideally I'd be happy to go bigger for the more comfortable ride, at the slight additional expense, but Im wondering if it'd really make any difference if I only went marginally bigger.

A more aggressice tread sounds like it'd look better, but if it would be noticeably noisy then I wouldn't be too keen. With the current tyres that are on it I don't really notice much in the way of the noise being very noticeable. Im wondering if these kind of things (noise, fuel consumption) would not really be that noticeable in real-world usage at all? I'm somewhat doubtful..?

Shallow and silly as it may sound, I'd like my tyres to be black and decent looking, given the choice.

mathepac

mathepac wrote: »

First port of call is the Owner's Manual to see what size tyre Toyota fitted originally and put four of them on the car. The fronts look bald.

I would suggest you steer clear of knobbly off-road tyres unless you will be doing knobbly off-road driving. They may look macho but they'll wear out quicker on regular roads, make more noise and will be less than good in the wet on tarmac. . Having said that, put enough back to black on any tyre and if it gets into the treads, you'll be figure skating for Ireland in no time.

Put Toyota recommended tyre sizes on, make sure they are a quality brand and matched to the conditions you will be using them in. Price / looks should be way down the list of criteria especially if you are transporting family.

I do a fair bit of wheel-spinning in wet weather alright. But usually it's only because Im an idiot and leave myself trying to rush around the place or panic on a hillstart when someone parks on my bumper. To reduce that should I be looking at deeper treads? Or am I looking at off-road-y tyres again?

(in my defence, I have seen others spinning wheels around the place, too, so could be just very slippery surfaces).


Is there an alternative to back to black sprays? I gave my car to a mechanic to get it serviced recently. When i got it back the tyres were brand new looking at it lasted about two weeks. Im guessing he actually painted them? Can I do that or is that as bad as spraying them?



EDIT: Apparently the actual thread on the front tyres are grand, so not bald, but it's the sidewall that's looking troublesome (cracking, etc.). They just look very bald in the photos and in comparison to the rear tyres (which are much more aggressive looking, which i actually like).

pete4130

AT tyres offer less grip on the road as they have bigger, deeper, more aggressive looking threads, meaning less surface area of the tyre in contact with the road. The deeper bigger threads help in preventing mud and sand clogging up when off road. HT tyres will offer best grip on the road so stick with those. HT tyres will have water channels to help move water from under the tyre to the outside and help prevent your tyres from sitting on top of water while driving and help prevent aquaplaning. AT tyres don't really have this so again HT tyres are the best for on road. There are tread depth indicators on tyres (like dimples in between some treads). When the tyre gets down to this indicator its time to change them.

The noise will be noticeable at motorway speeds. An increase in rumble type noise will be present. Fuel consumption could drop 2-3mpg as well with AT tyres.

check here http://www.exploroz.com/Vehicle/Tyres/SizeCalc.aspx to see the difference in tyre sizes between the 2 that you've got. It's a 10.5mm difference in circumference. Depending on where the odometer reads from (front or rear) it can affect your speed reading (when you're doing 100kmh you might actually be doing 103kmh) and that in turn will affect how many KM's your car has actually done compared to how many it says it has done but thats only a small amount if its a 3% difference.

I don't know about cars per se. I look up what I might need to know. Wth regards to tyres and gearing I've gone through it all with my old Landcruiser when I was getting new tyres for it. It's stock with 16's but to put on 15's means cheaper tyres with more choice but harder to keep the wheel size as it should be to avoid any up or down gearing with different sized tyres. I kept it on 16's and managed to get 5 brand new tyres cheap from a deceased estate.
Stock I had 7.5"x16R's (imperial sizing) skinny tyres and I had 2 options to keep the circumference the same. Go with 265/65/16's or 235/85/16's (identical in circumference). I wanted AT tyres as I do go out in the bush here in Australia, beach driving, 4WD tracks, up and down mountains etc..
I opted for the 235/85/16 as the wider 265's would be a lot more work for the engine (wider tyre, more rubber, higher rolling resistance, more work for the engine to do) as my Landcruiser is an old 4.2L, straight 6 with only 129bhp when new so there isn't a lot of power to spare in a 2.5 ton truck.

Give this a read and see the difference between the different tyre types.