correct tire pressure: the most underrated performance mod u can do
 

Hi my name is Ghost-Flame and I don't check my tire pressure enough.

Now that's that said, I admit to not checking tire pressure since August.

frnot tires 26 and 24, rear 28 and 26

I pumped them up to 30 front and 32 back.

I just took it for a ride and the steering felt much less "heavy". It was ever so quiet-er. It felt crisper when I stepped on the gas, also.

I watched the computer over a 20 mile ride and it was ticking up by fractions.

I'm leaving for a 400 mile trip in about 30 minutes and I will post my mpg. I'll drive it like I always do. I have not been able to exceed 17.5 mpg on a hiway trip lately.

I will post the results later tonight.

*Drop what you are currently doing and go check your tire pressure for you guys in Europe go check your TYRES. Okay?

PS.my daughters car was 10lbs below correct psi my wife's were better only about 4 lbs below correct. the 3 of us are going to save some gas today... Take that IRAQ!!

Yea the most neglected part of maintenance and tire wear. I made a post on another forum recently.

So I went to check my parents tire pressures because my father calls me and says, "what is this little circle light that has a stick in the middle?". I'm like how long have you had it. Oh about a month. So I go to check their cars out. 3 Toyotas. Two have that light on.

Not one car out of 3 had PSI higher than 14. My fathers had 9 in the front. Wow.

Everyone needs to understand that for every 10 degrees in temperature drop, equals to 1 PSI of wheel pressure drop.

So like Ghost suggested, go check your tire pressure. Or TYRE for out friends across the pond.

consider nitrogen as the compressed gas, I hear much good from those that can ignore the expense. here in der plains we can cover 60 degrees Fahrenheit temp change in 48 hours (a couple times or more) in the stupid months, so I decided it was worth it, pretty hard to keep up w'dat.

Wish someone could come up with a cap that was simply red or green, replace the OEM valve? that would definitely help.

I am a big believer in maintaining tire pressures. Last year I broke down and bought a small air compressor with a long hose with a gauge at the end (see links). Not expensive but makes checking and filling tires SOOOOOO much quicker and easier. I have 3 vehicles that I check every 2-3 weeks and there are always a few tires that need to be topped up by several psi.

I've also found the compressor is great for other small jobs where compressed air is needed in the garage...including blowing dust out of vents, etc. when detailing vehicles!

Campbell Hausfeld 6g Compressor and Inflation Kit | Canadian Tire

http://www.canadiantire.ca/AST/brows....jsp?locale=en

I check my tires every 2 weeks. When the X is used for long trips, I add an additional 2 psi to the BMW recommended pressure.

Great advice. BTW for every 10 degree temperature swing, you will lose/gain 1 psi. Here in New England, at this time of year, I check the tire pressure once a week.

I like to pump up my tires to above recommended as I get better MPG this way. My winter tires are at 39-40 PSI right now and my all seasons ae usually at 37 PSI. I sacrifice ride quality but tire wear is still fine.

Okay as promised. I just finished my aforementioned 400 mile trip. 350 of it was hiway at cruising speed 75 to 80 mph. the other 50 were town and country.

I take this trip monthly. I always set the computer to calc the mpg. it has been running 17.5 mpg with low tire pressure. Today, I'm glad to report that I averaged 20.1 with proper pressure. that's 2.6 mpg more. I know this is anticdotal but that's almost 15% higher. if it was 5% higher that would be good 10% would be awesome. It's just air. that's 12.50 per tank if those numbers hold up for city driving as well. I'll be checking my air pressure weekly from now on.

:thumbup:
Is your X5 a pre-facelift? Saying because of the mileage you posted.

^ my x is 3.0 2002. Built 11/00/01. E53. R u talking @ e70 facelift?

I am talking about E53. Facelift E53 models have better mileage. In fact the facelift E53 4.4i has better highway mileage than E53 3.0i. I have achieved 22+ mpg on highway in E53 4.8is.

I don't know. I did have all the computers replaced in sept. '11 and I stayed at a holiday inn express last night, thatought to count for something!

And, we all know how careful and strict the mfg'ers are simulating the EPA test method, especially lately with the hwy mpg targets they all chase. :rofl:

Fwiw, our '01 3.0 shows 20.8 on the OBC, which I have re-set only three times in ~80k miles/10 years. We do high 21s to 22+ regularly on road trips, by tank/arithmetic method, and that is with the screaming rpms at speed, in our 5 spd manual.

The VetteVert rolls along at ~30 mpg on any trip... :thumbup:

Yes, tire pressure is important. Maybe I am just more sensitive and diligent having 3 scoots to ride, (that often sit for awhile between rides), and car(s) that sit, combined with huge temp swings at our NC Mtn Joint...
GL, mD

I wonder if runflats would show a less dramatic difference.

Ghost Flame FTW... Before my truck was pulling to the right fairly heavily. Checked the pressures and sure enough needed lots of corrections to get to 32 front, 33 back. After it is like I just got alighnment! Runs smoother and steering more crisp. Amazing what a few PSI can make..