New RR 20” wheels - terrible MPG!!!!

[RattyMcClelland]

Honestly the wheel and the size won't make that much difference. Yes it will a little, no denying that but not 5-10mpg worth.

As I said I went from 17s to 19s and it made no difference.

Even before I put my 20s on the van the fuel economy wasnt great.

I think these engine run extremely rich on acceleration and very very lean on light throttle to make up the economy.

 

[chriscroft]

Your new wheel/tyre combo is around 6% larger rolling radius than the OEM's. So the mpg indicator will be 6% out, also your recorded miles on your odometer will be under recording by 6%, so you will need to adjust your full tank - full tank mpg also. But 6% is only about 2mpg extra, so not the difference you are looking for.

 

[CRD]

Your new wheel/tyre combo is around 6% larger rolling radius than the OEM's. So the mpg indicator will be 6% out, also your recorded miles on your odometer will be under recording by 6%, so you will need to adjust your full tank - full tank mpg also. But 6% is only about 2mpg extra, so not the difference you are looking for.

Well, going on the basis that standard fit on 16" wheels is now 205 65 16, the 275 40 20's are coming out at 8.3% bigger for both diameter (28.7" compared to 26.5") and circumferance (90" compared to 83.2" for standard) AND the fact that Range Rover alloys are extremely heavy, this will all have a significant impact on economy.

When I run my 19"s with 245 40 19 tyres, I lose approx 60 miles to the tank compared to standard wheels being fitted in my experience.

 

[chriscroft]

Well, going on the basis that standard fit on 16" wheels is now 205 65 16, the 275 40 20's are coming out at 8.3% bigger for both diameter (28.7" compared to 26.5") and circumferance (90" compared to 83.2" for standard) AND the fact that Range Rover alloys are extremely heavy, this will all have a significant impact on economy.

When I run my 19"s with 245 40 19 tyres, I lose approx 60 miles to the tank compared to standard wheels being fitted in my experience.

WOW 60miles per tank lost, that is alot of money over the life time of a van. Apparently there is 7.5% difference between an "A" & "G" economy rating of a tyre, so if you where at completely different ends of the spectrum between OEM "Blue Motion" tyres, and your fitted tyre that would explain 8.3+7.5= 16% ish which equates to 40mpg v 34mpg (if you do not adjust you calcs for true rolling radius)

 

[Loz]

I've got instantaneous mpg and average (think it's on last journey) I'm gonna do 4 x 60 mile work runs to get a good base reading thanks

Yes but you also get those in the long term mode, in the top right corner of the MFD when looking at mpg you will see either a small 1 or 2, try switching to 2 as this will give you the long term mpg.

 

[Loz]

The main issue with the bigger wheel is the wider tyre on the road and the increased rolling resistance that comes along with it. In @CRD s example above the difference is between 205 and 275 mm on the road.

 

[RattyMcClelland]

The main issue with the bigger wheel is the wider tyre on the road and the increased rolling resistance that comes along with it. In @CRD s example above the difference is between 205 and 275 mm on the road.

Yep. Overall diameter is overrated. The tire width makes the difference and will drag more but not 10mpg more.

 

[chriscroft]

Yep. Overall diameter is overrated. The tire width makes the difference and will drag more but not 10mpg more.

Yes, I'm sure that tyre width will make a big difference, I think the A-G rating is just for comparison purposes across different tyre makes/types, and has nothing to do with section width. A very wide tyre will not only have more mass; and more friction/rolling resistance; but there is a lot more scrub with alignment and the way it sits not only in a straight line, but even more so cornering.

 

[DaveyB]

Got 18" sportlines at the moment. Road trip today down to Southampton, then on to Poole, and back home. Left with just under 1/2 tank, reserve light came on 10 miles prior to getting home. 49mpg going down 45mpg coming back, 70mile still showing on the range computer and 570miles on the odometer since reset at refilling the tank.

I do a combination of short, medium and long journeys but it is quite normal for me to get circa 45+ mpg.

 

[ZipcodeUK]

Got 18" sportlines at the moment. Road trip today down to Southampton, then on to Poole, and back home. Left with just under 1/2 tank, reserve light came on 10 miles prior to getting home. 49mpg going down 45mpg coming back, 70mile still showing on the range computer and 570miles on the odometer since reset at refilling the tank.

I do a combination of short, medium and long journeys but it is quite normal for me to get circa 45+ mpg.

That's a Euro 5 for you!! You won't get that "49mpg" with the Euro 6. But then some say the mpg still gets better after vehicles done about 10-12k. I'm only just on 8k now.

 

[Buggirl]

I had 20 inch Range Rover alloys on my t5. Looked awesome, drove ok, but fuel economy wasn't that great. Took them off after 4 years and put 16 inch steelies on and mpg increased and drove so much better, hence me keeping my Deavonports on the T6. Each to their own, but been there done that and definitely got the tshirt!

 

[Jay Grundy]

Yes but you also get those in the long term mode, in the top right corner of the MFD when looking at mpg you will see either a small 1 or 2, try switching to 2 as this will give you the long term mpg.

How do I select that then??? Cheers

 

[Loz]

How do I select that then??? Cheers

Have a read of the attached.

 

[Jules]

Defo think its worth manually calculating your MPG tank to tank and see what the actual figure are, some people find the onboard readings to be way out

I just came back from the Alps on cruise control and my 4Motion reads 24.7mpg. Read the same on the way out there too. Is this my VW reading badly or just a crap MPG on the 4Motion?

 

[former member]

Or is it that only those with massive wheels are getting bad mpg?
Ours is fine and we're lugging a lot of camper weight.

 

[ZipcodeUK]

it's something thats holding me back from going with 20's and rather sticking with 18's. although I don't do a lot of miles, even not constantly getting hi 38's or 39's (mpg) frustrates me. I managed 42MPG on a 50mile round trip last week. Mostly A roads, quite a bit of stopping / going in traffic. I'm happy with that sort of MPG.

 

[mark]

The euro 6 doesn't seem to be a frugal as VW claim !

I wonder if cold weather plays havoc with the MPG, cold engine = dirty engine=lots of dpf cycles = lots of derv. The new engines certainly don't warm up in slow,cold conditions.

If you've a cali though the Aux heater will fire up below 5c so the engine warms up quick but that 5kw burner will slurp a fair bit of diesel that wont show on the MFD.

 

[Jay Grundy]

I just came back from the Alps on cruise control and my 4Motion reads 24.7mpg. Read the same on the way out there too. Is this my VW reading badly or just a crap MPG on the 4Motion?

Ouch!!!!!! I think the only proper way to check mpg is brim the tank and do the miles then brim it again and calculate it - I drove in to work today at just under 70 and managed a healthy 40+ even with the 20's on it!!

 

[Jules]

Ouch!!!!!! I think the only proper way to check mpg is brim the tank and do the miles then brim it again and calculate it - I drove in to work today at just under 70 and managed a healthy 40+ even with the 20's on it!!

Ouch indeed! I have not noticed a major difference since I changed the 17's to 20's but it certainly doesn't give me anything like the MPGs other people on this site are quoting. I admit I do not drive it at 50mph all day long which will attract criticism I know but still, even at a steady 80 mph on a relatively flat French motorway, you do expect better than 24.7!?!

 

[RattyMcClelland]

I urge everyone to find out their mpg buy brimming the tank, resetting the taco and resetting average mpg 2 as a guide and working out the average after a full refill and work it out that way. I can get my mfd 1 to read 40mpg no problem but I'm not getting that .


I was getting poor mpg on my 16s before I went to 20s. Made no difference.

However I notice I can get slightly better if I do 65mph not 70mph and warmer weather certainly makes a difference.
I'll see what this next take days as I reduced my motorway speed to 65 instead of the usual 70. Mfd 2 is saying 32.8, which it's highest yet towards the end of a tank

Still way worse than my Euro 5.