Tyres - what's best?

[Sebastian S]

Hej Micke!

I saw your syncro on 4x4sweden, looks good Nice to see another one on the west coast!

Besides engine, final ratio is what really matters when deciding on tyre size. If you're at 3000rpm at 60mph, with the tyres you have on now, you most likely have the 4.57 ratio. At least a bit better than the 4.86. I reckon don't go too low on load rating in a hi top, but I'm no expert. Calculating in the rather weak load rating of the 205's I would go for 215/75's. Don't expect miracles off-road though, you will be going a bit faster than optimal in G. But, only way to find out what really works for you is to try tires out.

And regarding SA syncros, they were RHD. ABS where a factory option, SA brakes probably fitted by a previous owner.

Here's a useful link: http://www.syncro.ca/tiresize/" onclick="window.open(this.href);return false;

[Sebastian S]

Also, if you could live with the wider tyres, I believe the AT2 grabbers are available in 225/70. As syncropaddy said, I tiny bit smaller and still good load rating.

[MickeTJ]

Hello Sebastian,

Yes they are not that common here in Sweden, at least not here on the west coast. I have never seen another syncro around here.

Now I have checked the gearboxcode and its the AVN22 with the 4.85 ratio.
But the weird thing is given these parameters, according to http://www.syncro.ca/tiresize/" onclick="window.open(this.href);return false;
215/65 r15 and 100 km/h should give an RPM of 3315.. I know for sure that I stay att exactly 3000 rpms and that gives 100 km/h.
Maybe someone has changed the R&P in the gearbox during the rebuild 2 years ago. ( I got the invoice from Holland, but does not show any change of R&P)

According to the tire calculator, same ratio but with the following tires at 100 Km/h
215/75 r15 = 3113 rpm -6,49%
225/70 r15 = 3146 rpm -5,37%
205/75 r15 = 3181 rpm -4,05%

I´ve reed here on the forum that the powerloss is like adding in the 215/75 r15 case 6,49% to the hills angle.
I´ve only had to downshift on one of the steepest highway inclines we have in Sweden, called "Hallandsåsen".
about 1/4 from the top. It got a 6-7% grade for about 3 km. So that would give instead of downshifting at 2,25 km I would downshift at 2,1 km.

That is not a remarkable difference in my opinon.

I think I go the middleroad, 225/70 r15 it is. Large enough to make a difference from what I got now.
and snowflake rated and 100 loadrating, wich I can bare in mind when swearing over the underpower
Unfortunately they are G rated and not F rated in fuel consumption but I can live with that 5% difference.

Last question,

would those tires rub on a 6.5 rim with ET38 ??

[tforturton]

Do you know what? I'm none the wiser.....

[max and caddy]

If your ring and pinion was swapped it would require the front one to be swapped as well..unlikely...also the re counters are not exactly accurate...nor are the speedos..

[..lee..]

QUOTE
Now I have checked the gearboxcode and its the AVN22 with the 4.85 ratio.
But the weird thing is given these parameters, according to http://www.syncro.ca/tiresize/" onclick="window.open(this.href);return false;
215/65 r15 and 100 km/h should give an RPM of 3315.. I know for sure that I stay att exactly 3000 rpms and that gives 100 km/h.
Maybe someone has changed the R&P in the gearbox during the rebuild 2 years ago. ( I got the invoice from Holland, but does not show any change of R&P)


sounds like maybe someone has put the .78 fourth in the box.

[syncropaddy]

I would reckon the rev counter and speedo together are simply not accurate. Speedo's are designed to read 4% fast.

225/70/15 will fit on a 6.5" rim

This thread has gone completely mad. The difference in performance will hardly be noticed no matter what final drive ration you have if you use 215/75/15 on a standard 14" Syncro. So many people are using that size and if it was wrong we would know about it by now! Its a good size for off road tyres cuz a good range is available. For simply road use a 70 series road tyre should give good results and be quieter

If the OP is lost at this stage my advice is

205/70/15 is a good road tyre size and a common one. It is also available with reinforced side walls. It will fit on a 6" Mefro real nice. If you have 6.5" Mefros rims get 225/70/15 road tyres.

[axeman]

i can understand how the speedo can be out, they are out on most cars and vans, but on a petrol how could the rev counter be out? it's signal comes directly from the coil?

neil

[MickeTJ]

Haha, Yup, I can agree that this tread has gone mad.

Maybe because I (and probably alot of others) would like to feel sure on a 6-700 € investment.
Now I feel that I have gotten answers to my questions.

I will buy the 225/70 r15 tire and be happy about it, at least I can´t afford to buy another set for a few years.

[Trundler]

I've just been quoted c.£75 (each) for Maxxis Trepadors in 205/70x15 * I like the look of them (quite gnaarly) but I thought they might be too aggressive for road use. However, comments on 4x4 forums are very positive both on road and off (apparently, many 4x4 owners use their vehicles on the road a lot.. )

Noise, grip and longevity all get top marks. The only slightly less positive comments are for ultimate grip in mud.

at £375 I think I might invest in a set of 5

* See Graham at Pennine Service Station on the A59 at Balderstone (between Preston and Whalley) - that price is fully fitted!

[MickeTJ]

I have just got the new tires on 225/70 r15.
No rubb at all, yet at least. (Only did some city driving back to the office)

About the power loss: (if someone will read this tread in the future).

Not that bad to me, but you will notice the difference when driving in the city. 40-50 km/h.
45 km/h is just between the 2nd and 3rd gear (around 2000 rpms). So you have to downshift to 2nd when going thru a roundabout.
luckily I hope to stay out of the city with a syncro so...

When factoring in the better looks and added ground clearance I would recommend this to any other novice like me

[tforturton]

I've just ordered a set of the General Grabber ATs (the new design with the diagonal tread pattern) in 205/75/15.
Bought via black circles website, they cost £427 ( for five) and are being fitted on Friday. I'll let you know how it goes...

[silverbullet]

I'm going to have to disagree with Andrew here

On the taller diffs (4.86 in my case) the bigger AT2 tyres definitely spoil the driving experience on metalled roads. The gaps between standard gear ratios is just a bit long when compared to a 5-speed 2wd on a 4.57 (where I don't even use first gear), I find myself rowing the syncro along and it's just a little tedious. I find myself wishing that it had another gear in order to close the ratios up.

All of which has nothing to do with the choice of engine! I know that's just fine, thanks

I'd like to go down a size and ratio from 215/75/15 to 205/70/15 when I have scraped up some dosh for some of those easy-rolling AT's for daily use. Mud tyres for playtime, AT's for the road.

There is no "best" tyre.

[toomanytoys]

Gotta agree with SB..
In my experience there is a difference when fitting bigger tyres to a stock 14.. especially if you have come from 185's.. (on 4.86 final drive also)
I have been running 185's most of the time in ownership (80k km +) and swapping to the mudder 205/70r15's does knock the performance a bit..

If you have 14" rims and cant afford to go to Mefro's etc.. this bit will be of interest...
4 weeks ago I fitted some 205r14 Yokohama Y354's.. after seeing Aidan performing well on them at a very slippery Coney Farm.. and I needed a new set of all seasons/AT as the winters were out..

Just done "ahem" thousand km to Croatia and back on them..
A little drop in pulling performance, but the better cruising ability more than made up for it.. speedo is now maybe 2-3km out at 100kmh, great to be traveling at what the speedo says rather than a good 10% less...
For an all season tyre they perform very well.. and they have proved themselves on slick muddy fields, gravel tracks, boulder infested forest tracks that hadn't been driven in 6 months. High mountain passes and v hot sunny days.. hours and hours on the motorway and the last 24 hours back through Germany and Belgium, miserable pouring rain...

If you are sticking with 14" rims.. and want a tyre for all year use that allows some offroad capability and winter approval.. then I don't think there is much better out there.. certainly much better than the winter vans I was running which were great in most conditions but were useless on wet grass...