Miles Per Gallon? 37 For The T Sport. How To Improve?

[carlowlad]

High tyre pressures is the poor-man's low friction tyre ;)

What pennies you may save in over inflating your tyres is wiped out when you have to buy new ones prematurely due to excessive wear, plus any damage repair and insurance excess when you go flying off the road!

Tyres don't normally wear out in the centre at higher pressures. My last car had tyres on it for 100,000km and they finished up with 4mm tread on them. Even wear too. I measured it with a tread gauge. If you read my earlier post you'd have seen that what you say is a generalisation. My fellow hypermilers have all reported even wear and most have said grip is unaffected. Of course, they drive on smooth roads. Some of mine are a little bumpy so a harder tyre complicates things a little. Perhaps some stiffer shocks might keep the wheel on the ground with harder tyres?

I read an autospeed article about tyre contact patches and it confirms what i say. Also look at http://www.stevemunden.com/friction.html

Thats cold hard mathematics. Argue with it!

You mentioned insurance problems with harder tyres. Thats something i'd like to hear from someone who works in insurance. From the horses mouth so to speak.

[carlowlad]

Here is the autospeed article i mentioned in my last post: http://autospeed.com/cms/title_Tyres-Grip-...15/article.html

Should help clear things up!

[Cyker]

I get about 39-42 in my school car.. a 1L model..

and around the mid to upper 30's in my own 1.3L but that is an automatic!!!

I am thinking about a Fabia Greenline for the school one.. They are reconed to do mid 60's in town, low 80's on th m-way.. Deisel though so bit dearer fuel but 35 notes tax! My 1.l is now £150 anually!!!! daylight effin' robbery for such a small clean car!

Yeah, that was part of the reason I went diesel too; My old 1.3L Fiesta (Which was actually less powerful than a 1.0L Yaris!) was getting hit for £180 at one point which was the same as my dad's 2.2L Merc Estate!!!

But hey, if the government prefers carcinogens and soot to CO2, who am I to argue? :P

And round here I'm actually well up on petrol users; At a few fuel stations it's 100.9 for standard unleaded and 101.9 for diesel!!!

High tyre pressures is the poor-man's low friction tyre ;)

What pennies you may save in over inflating your tyres is wiped out when you have to buy new ones prematurely due to excessive wear, plus any damage repair and insurance excess when you go flying off the road!

Well we're not talking ridiculous levels of over-inflating here; 40f/35b is what my Yaris manual recommends for a heavily loaded Yaris. I just run that all the time :P

If you go another 10 or so above that, then the tyre will probably start to bulge which is when you get the extra centre-line wear, but at the levels I'm doing it there shouldn't be any danger of that; I've certainly never noticed any extra wear before.

I did find carlowlad's articles interesting 'tho. My experiences about the aquaplaning don't really match up (In the very rare occasions I'm driving quickly on country roads in the rain, the car feels a bit more skittish on corners, whereas the article reckons higher pressures = less aquaplaning!), but I do find that the sidewalls stay in better condition for longer.

Not sure how much of this helps the OP 'tho

[carlowlad]

Not sure how much of this helps the OP 'tho

True! The biggest factor affecting mpg is driver behaviour.

As for higher pressures in tyres? Well, if you drive normally, it won't make a whole lot of difference, other than your tyres lasting longer (given the cost, thats not too bad!). But if you slow down and really watch your mpg you'll notice a fair improvement. I've noticed that at higher mpg numbers, little things start to make a big difference. At regular mpg numbers you could stick a Roof Rack on and hardly notice a difference. Take the extreme mpg contests, where they are on glorified bikes with a bullet shaped fairing to cover the driver. They can do 2000mpg. Thats not a mistype. Now, if they stuck their hand out the window they would lose a few thousand mpg. If you or i did that in our car, we'd hardly notice the difference.

For laughs, here is some links to some of the eco-marathons, as they call them: http://www.autobloggreen.com/2008/04/13/ne...thon-2-843-mpg/

http://www.autoindustry.co.uk/articles/18-07-05

It's a brave new world out there!!

[Cyker]

Yeah; The main reason I started running at higher pressures is I found the car would roll noticably longer.

I'm usually pretty good at looking ahead, and can get off the power while in 4th or 5th and roll up to the lights (using no fuel!). Diesel engines tend to have a lot less engine braking than petrols, and that plus the extra tyre pressures have increased the distance I can safely lift off the accelerator and roll quite noticably :)

It's probably not a huge thing, but it does add up. 600mile on a tank with mostly town driving is all the proof I need :D

[EchoRange]

Last fuel up I worked out 35.7 MPG for my Corolla, (T-Sport petrol) but I would like to share a little tip I've picked up esp in hot weather.

If you're like me, I drive with the windows down, to save using the air con. Roll them up and use the air con if you're still hot over 50 mph as the drag from the window is worse for your fuel. (I very rarely do, but when I was sticking to the leather seats the other day, it was such a nice feeling)

Now, I've heard some noises about people throwing acetone into their tank as a fuel addative. Anyone else heard this?

[Cyker]

Last fuel up I worked out 35.7 MPG for my Corolla, (T-Sport petrol) but I would like to share a little tip I've picked up esp in hot weather.

If you're like me, I drive with the windows down, to save using the air con. Roll them up and use the air con if you're still hot over 50 mph as the drag from the window is worse for your fuel. (I very rarely do, but when I was sticking to the leather seats the other day, it was such a nice feeling)

Now, I've heard some noises about people throwing acetone into their tank as a fuel addative. Anyone else heard this?

Yeah, good tip about the A/C :)

I really should use mine more; Apparently you're supposed to use it regularly to keep it in good shape anyway!

Have heard about the acetone thing, but mainly for petrol. Supposedly it lets the fuel vaporize a bit easier but the downside is that over a long term it can eat away at some seals/hoses, and in a few cases was suspected of causing damage to some sensors.

That said, there's a few threads here where people have tried it (e.g. http://toyotaownersclub.com/forums/index.p...howtopic=44575), and they haven't had any problems so far so YMMV ;)

Edit:

Well, on the one hand we have thisa: http://www.pureenergysystems.com/news/2005...900069_Acetone/

And on the other we have this: http://www.fuelsaving.info/acetone.htm

[HowardL]

Last fuel up I worked out 35.7 MPG for my Corolla, (T-Sport petrol) but I would like to share a little tip I've picked up esp in hot weather.

If you're like me, I drive with the windows down, to save using the air con. Roll them up and use the air con if you're still hot over 50 mph as the drag from the window is worse for your fuel. (I very rarely do, but when I was sticking to the leather seats the other day, it was such a nice feeling)

Now, I've heard some noises about people throwing acetone into their tank as a fuel addative. Anyone else heard this?

Yeah, good tip about the A/C :)

I really should use mine more; Apparently you're supposed to use it regularly to keep it in good shape anyway!

Have heard about the acetone thing, but mainly for petrol. Supposedly it lets the fuel vapourize a bit easier but the downside is it can eat away at some seals/hoses.

Its very important to use the A/C regularly,

It keeps the important seals lubricated,

If you dont use, the seals will harden and fail leading to leakage.

[carlowlad]

The acetone is debatable. Currently going on at http://ecomodder.com/forum/showthread.php/...ottom-2484.html

I personally think the risk of corrosion outweighs the theoretical benefits.

Re: diesel engine braking. It sure is minimal! When the hill is steep enough, which isn't really steep at all, i leave it in top gear and use no fuel all the way down the hill. Really helps getting my numbers up and i currently clear 800 miles to a tank.

I do mostly open road driving so i leave my windows closed. In an urban situation though, you can open them up as the aero drag is non existant. Early anticipation of the traffic and lights will help more. No point gunning it up to the red light now is there!!? DFCO all the way for me. They might be green when i get there so i come back on the pedal gently while looking for the next, invariably red, light.

ollie

[mrashaikh]

i got a t sport n normally gt between 37 n 45. i would defo agree with the ac n window relationship tho.