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Chat Area => General Discussion Area => Topic started by: Marks DTM Calib on 23 September 2008, 08:26:34

Title: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 08:26:34
Been playing with the tyre pressures and noting the mpg (over many runs).

Have now settled on the following which seem optimal from a handling and mpg perspective for a car driven on lots of motorway at speed.

36psi front and 36psi rear.
Title: Re: Interesting Tyre Pressure Results
Post by: cem_devecioglu on 23 September 2008, 08:45:12
Interesting..
36 psi.. Dont you feel the car is a bit jumpy ?
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 08:48:10
Quote
Interesting..
36 psi.. Dont you feel the car is a bit jumpy ?

Nope, the average speed i do is 54mph (whole trip) and the above sets the front to load pressure and the back to a mid point (equal to teh front which maintains the balance quite well).

Increasing the backs further did make it more jumpy (not surprising as its not loaded) but the above seems the best compromise.

Lowering it increases the mpg quite a bit.
Title: Re: Interesting Tyre Pressure Results
Post by: cem_devecioglu on 23 September 2008, 08:51:22
Quote
Quote
Interesting..
36 psi.. Dont you feel the car is a bit jumpy ?

Nope, the average speed i do is 54mph (whole trip) and the above sets the front to load pressure and the back to a mid point (equal to teh front which maintains the balance quite well).

Increasing the backs further did make it more jumpy (not surprising as its not loaded) but the above seems the best compromise.

Lowering it increases the mpg quite a bit.

I will try tomorrow :y
Title: Re: Interesting Tyre Pressure Results
Post by: Mr Skrunts on 23 September 2008, 08:52:00
Quote
Quote
Interesting..
36 psi.. Dont you feel the car is a bit jumpy ?

Nope, the average speed i do is 54mph (whole trip) and the above sets the front to load pressure and the back to a mid point (equal to teh front which maintains the balance quite well).

Increasing the backs further did make it more jumpy (not surprising as its not loaded) but the above seems the best compromise.

Lowering it increases the mpg quite a bit.

Interesting findings.  Just had a look at the OOF flyers to see what the standard rateings are.  Your findings fit the average for the normal and full load rateings.

http://www.omegaowners.com/forum/YaBB.pl?num=1184621237/all

Scratch that, I only read the bottom ratings on the flyer and they were for the estate.  :-/


Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:07:02
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.
Title: Re: Interesting Tyre Pressure Results
Post by: JonArgraig on 23 September 2008, 09:07:59
Quote
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.

what did you find best for the MPG?
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:11:45
Quote
Quote
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.

what did you find best for the MPG?


The above was giving me 38.8mpg (65mph, 2.5V6 manual), any higher and the improvements were marginal but the car became to bouncy....hence the above compromise.
Title: Re: Interesting Tyre Pressure Results
Post by: cem_devecioglu on 23 September 2008, 09:11:57
Quote
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.

Phew..long experiment..I dont have this patience ;D
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:13:48
Quote
Quote
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.

Phew..long experiment..I dont have this patience ;D

When your doing 500 miles per week its easy to do.....plus I need a car that gives good mpg but, can still catch people out at roundabouts  :y

Beleave me, I would not want to compromise the handling!
Title: Re: Interesting Tyre Pressure Results
Post by: cem_devecioglu on 23 September 2008, 09:17:07
Quote
Quote
Quote
They actually match the load speed settings for the front with the front pressures used on the back which keeps it balanced.

I should add that these are the results of 3000miles of trials and I have been running them for about 500 miles so far!

I suspect they would also suit an unloaded estate.

Phew..long experiment..I dont have this patience ;D

When your doing 500 miles per week its easy to do.....plus I need a car that gives good mpg but, can still catch people out at roundabouts  :y

Beleave me, I would not want to compromise the handling!

 :o

Marks DTM..Thats a long distance ..I'm afraid your fuel costs are very heavy.. :-/
Title: Re: Interesting Tyre Pressure Results
Post by: Mr Skrunts on 23 September 2008, 09:22:45
As a matter of interest, what size are the tyres/wheels.  Cheers :y
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:30:03
225-55-16 (its a CDx)....not that the tyre size affects the Omega tyre pressures on the 16 inch and 17 inch rims and even thats only on the estate  :y
Title: Re: Interesting Tyre Pressure Results
Post by: Dazzler on 23 September 2008, 09:32:57
Will this not be classed as over pressure slightly and thus wear the centre of the tyre down quicker????
Title: Re: Interesting Tyre Pressure Results
Post by: tunnie on 23 September 2008, 09:35:52
can't see why, its 40+ psi in the handbook for a fully loaded car.
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:40:00
Quote
Will this not be classed as over pressure slightly and thus wear the centre of the tyre down quicker????


Note that its at speed though which does increase tyre loading slightly anyway.....would not recommend these for round town because i have not tried them in that scernario!

Certainly, the tyres are wearing evenly though...
Title: Re: Interesting Tyre Pressure Results
Post by: Marks DTM Calib on 23 September 2008, 09:40:56
Should have also added that the readings are taken with a quality PCL tyre gauge!
Title: Re: Interesting Tyre Pressure Results
Post by: Mr Skrunts on 23 September 2008, 09:44:41
I normally put 32psi all round (just habbit I suppose)

When I do use the car, I nip arround the village a bit but allways tend to take it for a bit of a run.

Am tempted to put mine up to 36psi all round.  Last time out I nipped to Mablethorpe on the Motorway returning 30 @ 50mph ave in fog and 32 @ 72 ave  coming back in a 3.0 so cant se why 35/37 mpg couldnt be achieved if I actually did 70mph  ;D ;D ;D ;D
Title: Re: Interesting Tyre Pressure Results
Post by: tunnie on 23 September 2008, 09:46:34
i have been putting 31 PSi in mine (book says 30.5) so might try cranking it up.
Title: Re: Interesting Tyre Pressure Results
Post by: cem_devecioglu on 23 September 2008, 09:49:19
Winter 32-33 psi

Summer 30-31 psi generally..
Title: Re: Interesting Tyre Pressure Results
Post by: Mr Skrunts on 23 September 2008, 09:50:14
Quote
Should have also added that the readings are taken with a quality PCL tyre gauge!

Mine are normally done by my mate at his local garage, the day before I went to Mable thorpe I used one of those auto display ones at Morrisons and 32psi all round.

Old tyre pressures were 31 and 33 on the rears, and the fronts had dropped to 26 and 29 since last checked by my mate about 8 weeks.  only used the car twice in that time.

Will use the auto one again next weekend to see if there is a drop in psi over 2 weeks

Also found I had a wheel vibration at *5 Mph which needs sorting
Title: Re: Interesting Tyre Pressure Results
Post by: nick v6 on 23 September 2008, 11:34:32
i run mine at 36psi front and rear with 17inch wheels and have no problems with it jumping or anything and it handles great

i had it scream like a virgin on a few islands at high speeds lol
Title: Re: Interesting Tyre Pressure Results
Post by: TheBoy on 23 September 2008, 12:48:58
On the MV6, I tried some experiments about 2 yrs ago, and ended up 32f 35r

This provided best compromise of handling/mpg and tyre wear (rears were doing edges).

I tried increasing front, but it made the awful understeer that the MV6 seems to have even worse  (not sure why MV6 shows understeer tendency, suspect its to do with the less than perfect wheels)


Tractor runs 32 all round, must more, and it makes it a bit 'skittish' in the wet.
Title: Re: Interesting Tyre Pressure Results
Post by: The Barge Captain on 23 September 2008, 12:57:55
I went over to visit JasonH on the weekend and he was saying then that all Omegas seem to be running too low pressure on the back judging by tyre wear.

Mark's figure which is about half way between laden and unladen even without his exhaustive testing does seem like a good figure to use.
Title: Re: Interesting Tyre Pressure Results
Post by: Banjax on 23 September 2008, 13:07:54
just went to check my pressures - 50p for air!!!!!!!!

i remember paying 20p and thinking that was bad enough

what happened to free!! >:(




i keep em at 32psi all-round all year - seems OK - but i'll maybe nudge them up a bit having read these posts  ;)
Title: Re: Interesting Tyre Pressure Results
Post by: nick v6 on 23 September 2008, 13:30:10
Quote
just went to check my pressures - 50p for air!!!!!!!!

i remember paying 20p and thinking that was bad enough

what happened to free!! >:(


nearly all the petrol stations in my area do free air and water
then go and charge about £1 for 5mins to use the hoover right nest to the air and water machine

i keep em at 32psi all-round all year - seems OK - but i'll maybe nudge them up a bit having read these posts  ;)
Title: Re: Interesting Tyre Pressure Results
Post by: Taxi_Driver on 23 September 2008, 19:03:16
I guess tho......that a 4pot would be better with less than 36psi on the front....less weight  :-/

I put 30psi in the front......most of my driving is plodding around town....i usually have av speed according to the comp of 19mph.

I did try putting 38psi in the back once (when i had a slow puncture) and boy was the ride harder.....i could feel the bumps more even sitting in the front! Back down to 33psi now.