Info please
Printed From: Bavarian-Board.co.uk - BMW Owners Discussion Forum
Category: Technical & Model Specific Forums
Forum Name: BMW 8 Series
Forum Discription: This forum will deal with any issues on the E31 BMW 8 Series
URL: http://www.bavarian-board.co.uk/forum_posts.asp?TID=17719
Printed Date: 29-April-2024 at 13:38
Topic: Info please
Posted By: dave635
Subject: Info please
Date Posted: 16-May-2005 at 09:55
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Hi there, can anyone advise the recommended tyre pressures for an E31 with the 235/45/17 front & 265/40/17 rears ? thanks, Dave. |
Replies:
Posted By: aussie840
Date Posted: 17-May-2005 at 04:18
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hi dave I have found at least 38psi all round give best results which is roughly what factory reccommends. Thats for a V8 E31. regards ian ------------- http://home.iprimus.com.au/charlew/e31/840-1.jpg"> 
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Posted By: dave635
Date Posted: 17-May-2005 at 08:21
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Thanks Ian ! |
Posted By: Paul_540i
Date Posted: 19-May-2005 at 17:08
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On a similar subject, would it be OK to put 255/40x17 on the rear?
There are very few tyres made in 265/40x17 limiting the selection (even
Goodyear Eagle F1 are available only in the old design GSD-2, while the
235/45x17 are GD-3). The E34 540i and M5 came with the same wheels as the 840, but with 235/45 front and 255/40 rear, so there's no problem with the wheels. The only thing that concerns me is the slightly reduced rolling circumference giving a slightly higher speedo reading but more importantly possible ABS/ASC+T issues. I doubt the difference is enough to cause problems, but would like to hear if anyone else has tried switching to this size at the rear. Cheers Paul. ------------- 540i 6-speed manual (sold) 840Ci 6-speed manual (sold) 318is (sold) Yamaha R1 (sold) |
Posted By: aussie840
Date Posted: 20-May-2005 at 19:06
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Hi Paul, You could get away with it, I have read of some in the States doing the same thing. In not should not affect the ASC because it activates if there is difference between the two rear wheels rotational speed (which can can be caused by different sized tyres), but yes it will affect your speedo reading a little bit. See http://gs.tolan-hoechst.com/tirecalc.htm - http://gs.tolan-hoechst.com/tirecalc.htm The M5 has the same size rear wheel but a different offset. Personally I would stay with the 265's. Does your MOT check for speedo calibration? Does your insurance policy allow to run non factory spec tyre size? Have you tried looking at Yokohama Sport AVS? They are great tyres at a reasonable price. I have them the best so far for the 8. See yokohama.co.uk Ian |
Posted By: Andyboy
Date Posted: 20-May-2005 at 19:12
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I had Michelin Pliot Sports on my '97 840Ci. Very
good indeed! I ran them with 5 psi over standard figures - I found the ride to hard when set at the highest setting. Mine also had the M5 type throwing star wheels. |
Posted By: Paul_540i
Date Posted: 23-May-2005 at 07:09
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Ian, The MOT doesn't check speedo calibration, and the law allows for the speedo to over-read by some percentage as long as it doesn't under-read. So it's probably still within limits. Never heard of insurance issues either, as long as the change is slight and safe in terms of being a compatible size for the wheel. Yokohamas... well they aren't really suited here for one reason: rain! We get lots of it, and IME Yokohamas don't deal with wet roads well at all. So I'd rather not go for those. The only tyres available on mytyres.co.uk that are available in both 235/45 and 265/40 that look decent are Bridgestone S-03 (which may be too soft for high mileage use) and possibly Toyo Proxes T1-R but these are new so I don't know enough about them. I am actually considering upgrading to 18" M-parallels so that may solve my tyre dilemma! ------------- 540i 6-speed manual (sold) 840Ci 6-speed manual (sold) 318is (sold) Yamaha R1 (sold) |
Posted By: aussie840
Date Posted: 26-May-2005 at 07:30
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Hi Paul, I beg to differ on the Yokis in the rain, occasionally inbetween months of drought it rains heres too and I found the Yoki's braking performance better than the Pirelli or BF Goodrich by far. Have you tried the AVS in the wet or another tread? I have found my ASC kicks in about 50% less with Yokis on. However I acknowledge they do handle better with a little bit of temp in them...and although I've been to London, Scotland & Ireland a few times but never in winter I have heard and read in books that it get can below 5degC sometimes. In which case maybe the Yokis wouldn't suit that climate? Also IMO throwing stars are the best looking wheels for the 8 - even better than 18" parallels - but that just my thoughts! Ian |
Posted By: Paul_540i
Date Posted: 03-June-2005 at 12:14
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Yes it can quite easily get below 5deg in winter. I had the OBC "bong"
at 3deg quite a few times in my 540 last winter. Usual winter temps
tend to be around 8-10deg during the day and 0-5deg in the evening in
Scotland. I haven't tried Yoko AVS but I did have another type of Yoko sport tyres on a previous car and they were definitely much more focussed on performing in the dry than the wet. Never tried BF Goodrich but they're not popular over here so I guess they're not really favoured for wet climates. Pirellis I don't like at all, just removed a set from the front of mine (fitted by previous owner) and I couldn't get rid quickly enough. A previous car of my dad's had P-Zero and they were lethal in the wet, pathetic for tyres costing £140 each. My favoured brands are Goodyear Eagle F1 or Bridgestone S-03, both of which I had on my previous Impreza WRX and both were excellent in the wet compared to most other tyres I've tried. I had Michelin Pilot Sport on my 540 and they appeared very good but expensive, and also had Dunlop SP-Sport 9090 on the 540 which appeared very good in the rain. The only thing that really concerns me about the Goodyear Eagle F1 is the wear rate which may see them scrubbed quickly on the 840. I was happy with them on my Impreza, but that's a much lighter car and my mileage was much lower as I only used it as a weekend car. Otherwise I'd have a set of them in an instant. Have a look at these pages, which are formed from a collection of reviews from people who have purchased the tyres: http://www.tyretest.com/pkw_sommerreifen/goodyear/eagle_f1 /index.html http://www.tyretest.com/pkw_sommerreifen/dunlop/sp_sport_9 000/index.html http://www.tyretest.com/pkw_sommerreifen/yokohama/avs_spor t/index.html http://www.tyretest.com/pkw_sommerreifen/bridgestone/s_03_ pole_position/index.html Admittedly the sample size is variable so it's not an ideal comparison, but it does show that those reviewers aren't too impressed with the Yokos wet weather performance. Paul. ------------- 540i 6-speed manual (sold) 840Ci 6-speed manual (sold) 318is (sold) Yamaha R1 (sold) |