|
||
|
23rd October 2019, 13:07 | #11 |
Gets stuck in
None at the moment Join Date: Jan 2018
Location: Hereford
Posts: 501
Thanks: 1
Thanked 165 Times in 146 Posts
|
Without knowing the specific fuel consumption curve for the engine , one cannot really say what the effect will be by altering the engine revs at the same road speed . If say at 70mph the engine is running at its optimum speed for fuel consumption, altering it either way will make it worse. If though it moves the engine speed to a more favourable part of the curve it will be better, but if it moves to a less favourable part it will be worse. One is also moving it about on the torque and power curve as well so you end up with multiple effects . I suggest moving it by 2.5 % is unlikely to show a noticeable effect. One is more likely to notice the ride changing.
|
23rd October 2019, 16:33 | #12 |
Avid contributor
Rover 75 Conny SE Starlight Silver Join Date: Dec 2014
Location: Coventry
Posts: 107
Thanks: 59
Thanked 24 Times in 17 Posts
|
Hi
I'm only thinking of changing as I've just bought my latest conny with 16" forks that really don't do it for me in the looks dept and tyres are all pretty close to the limit and require replacement. As there are a few sets of 18s on tinternet with newish tyres at around the £100-£150 price range so was going to kill 2 birds with 1 stone so to spk. Many thanks for all your input Col |
23rd October 2019, 18:42 | #13 |
This is my second home
Rover75 and Mreg Corsa. Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
|
To be sure your chosen wheel/tyre combination complies with the spedometer regulations and for your insurance to remain valid, I'd suggest you stay within the sizes recommended in the Handbooks.
2004 Handbook (introduced 18" rims) Last edited by T-Cut; 23rd October 2019 at 18:47.. |
25th January 2020, 17:21 | #14 |
Gets stuck in
Rover 75 Diesel Tourer, called Perseverance Join Date: Nov 2011
Location: Bournemouth
Posts: 664
Thanks: 189
Thanked 157 Times in 108 Posts
|
Honest John recommends that tyres should be a minimum of '55 profile to avoid rim damage due to potholes in the UK. Seems sensible advice. A blowout at high speed due to pothole damage does not bear contemplating, simply for a 'nicer' look. You only have one life.
But it is your choice. Last edited by MarkS; 25th January 2020 at 17:34.. |
25th January 2020, 18:18 | #15 |
Posted a thing or two
75 cdti 2004 contemporary Join Date: Apr 2008
Location: meath
Posts: 1,551
Thanks: 272
Thanked 80 Times in 58 Posts
|
The 18 inch do fill the wheel arches better but car will be higher off ground unless the springs are shorter.
My car had 18 inch when I bought it but went back to the 16 inch . Car sits at correct height now and ride much better. I am sure the mpg was slightly worse with the 18 inch but then it may have been the tyres. |
Thread Tools | |
Display Modes | |
|
|