265/65/17 to 265/70/17 how much difference?

[Troy1 Member Find all posts View Profile Close Troy1]

Thanks for the info guys ill have to look into getting it engineered! Havent checked the nsw list of approved signatories by the RTA or RMS or whatever they wanna call themselves these days! But last time I checked early this year they culled the list by half! So my closest was hours away in sydney. :-( Unfortunatly none of the tyres i want are in 265 65 17

[Guest Close Guest]

The good tyres are usually 265/70R17. So maybe change to an FJ and you won't have certification hassles.

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

There is always the option of going to 275/65/17 tyres which are a bit larger than standard but fall with in the lagal limits for tyre size upgrades, people may want to confirm each specific brand in that size and double check state laws but from what I have read they should be OK almost anywhere.

Cheers Andrew

[SWR Banned Find all posts View Profile Close SWR]

Hi guys

Here is the actual Tyre formula as appose to counting on web-sight calculators

TYRE FORMULA:

EG: for 265/65/17

Tyre width (265mm) times (65%) percent of Tyre width = side wall height equals 172mm

Now convert 17" (Wheel Rim Size) to metric (25.4mm to 1") = 431.8mm

Now add side wall height 172mm x2 = 344mm

Now add both the rim size and total side wall height together and you will now have a total wheel diameter of 775.8mm so round it up to 776

Using the "current" RTA (soon to be (RMS) Roads and Maritime Services) for legal Tyre sizes in NSW of 15mm total diameter to vehicle manufacture Tyre placard.

####################################
STANDARD SIZE
Specification -- Sidewall -- Diameter
265/65-17 --- 172mm ---- 776mm

####################################

This tyre is 2mm under legal max Dia
and has a 10mm bigger foot print.

LEGAL SIZE = 275/65/17
Specification - Sidewall -- Diameter
275/65-17 --- 179mm ---- 789mm

####################################
This tyre is 12mm over legal max Dia limit

NEED ENGINEER CERTIF
Specification - Sidewall -- Diameter
265/70-17 --- 186mm ---- 803mm

Cheers

[Dusty74 Senior Member Find all posts View Profile Close Dusty74]

That's all great but what I think Troy was trying to find out is how to fit a 70 series profile tyre, mainly because all the popular brands only come in that profile (for a 17" rim anyway). It is frustrating to say the least that either Toyota or the tyre manufacturers could either fit 70 profile tyres to begin with or make bloody tyres in 65 profile! Better still Main Roads could pull their heads out and permit a profile increase, not a bloody stupid measurement that doesn't relate to anything. i.e. 15mm dia increase.

Just my rant, sorry,
Cheers,
Dusty

[D4D Addicted PP Member Find all posts View Profile Close D4D]

You could move to MEL where you can run 70s

[Dusty74 Senior Member Find all posts View Profile Close Dusty74]

But then I couldn't sit here in my boardies and T-shirt in God's country!
Cairns is awesome, plain and simple!

[SWR Banned Find all posts View Profile Close SWR]

Gday Dusty74

Quote: That's all great but what I think Troy was trying to find out is how to fit a 70 series profile tyre

Answer: I personally wasn't trying to answer Troy's question but giving general knowledge for anyone who doesn't understand tyres in general!

What you think and what the law says makes your opinion irrelevant in court if caught!... Difference of opinion is a fare call but so are the tyre regs when putting safety first.

Quote: Main Roads could pull their heads out and permit a profile increase, not a bloody stupid measurement that doesn't relate to anything

Answer: If there is no law on tyre size then there would be a pile of cars breaking speed limits (Un-wittingly) due to speedo's running slower than actual speed. (hence engineer certiff with brake system up-grade (if they think necessary) and re-calibration of speedo)... By forcing this as a law it keeps most cars safely within actual speed limit according to speedo reading but all this goes out the window with bigger tyres... Hence a law in place.

You "CAN" have bigger tyres but it has to be re-certified to remain certified as safe.

Quote: a bloody stupid measurement that doesn't relate to anything. i.e. 15mm dia increase.

Answer: Same as previous answer.

Cheers

PS. No ranting intended Lol

[Dusty74 Senior Member Find all posts View Profile Close Dusty74]

Yep, not arguing with you there. My points were born through frustration. Tyres the size that fit our vehicles legally without certification are extremely limited, especially off road oriented designs. Instead of a 15mm dia increase, a single profile increase (same width) would only see an average increase of about 10_15mm over the 15mm already allowed. That way you could actually fit x, y, z brand tyre. If it's not a problem in other states to do this, I don't see the need for going over the pits/ certification for what is a minor modification. Federalisation of these laws would, I hope, would see us brought up to Vic's standard and hopefully not everyone back to ours!
Finally, I wasn't aiming my post at any particular post, just a generalization of the topic overall.

Cheers,
Dusty

[Troy1 Member Find all posts View Profile Close Troy1]

Thankyou everyone for your input

[Trouchet Lurker Find all posts View Profile Close Trouchet]

Hi all has anyone had any problems with loss of power when towing after fitting the 265/70r17
the tyre shop told me my 150 may jump in and out of gear when towing. I have a 2018 model auto
can anyone shed any light on this ?
Regards Tim

[chloe123 Lurker Find all posts View Profile Close chloe123]

Never heard such crap in my life. I’ve had 4 prados, all had tow bars, all auto, 3 of them lifted, 3 with higher profile tyres, never had an issue. You will notice higher fuel consumption even with out towing because your pushing larger rubber but nothing major. Sounds like they had no idea what they were talking about

[Guest Close Guest]

Hi all has anyone had any problems with loss of power when towing after fitting the 265/70r17

There's no point fitting 265/70R17 if you are only towing and touring around. There will be a small power loss but you don't really realize it going one size up but you will know when you regained that power after you go back down to 265/65R17.