Excessive petrol consumption?

[H3XME]

31 minutes ago, Lex_utor said:

About the wheels, I have been just following the manufacturer's recommended tyre pressures on the door jamb for my 19" as well. Does the IS-F has different recommended tyre pressures for its 19" wheels?

My front tyre kind of looks a bit underinflated. See photos of my tyres thread wear bellow.

 

Front:

 

 

Are they some Chinese tyres? Regardless.. They tyre bill fine. I drift on 65psi which is obviously more than what tyre states and it's fine. Either way, running tyre pressure at 40 and 45is fine. I do. But I have camber and stretched tyres. I need to run higher pressure tbh.

[Linas.P]

Just to clarify - so what pressure were you using? Because I am certain IS250 does not have pressures for 19" on door jam as such wheels were not fitted to IS250. IS-F has different pressures, because it has 235/265 tyres, so that would not be suitable for you unless you have 235/265s on 8.5/9.5J wheels. In general I would expect larger wheels would require lower pressures, if memory serves RC200t with 235/265 wheels required 22-24PSI, compared to 30-36PSI on 18". 

Under inflation could hurt fuel consumption massively - like 20-30% depending on how badly underinflated are the tyres. But looking at your tyres they don't look underinflated, they look like they are wearing on the edges which is common on IS250 and other Lexus cars... and assuming you put 30PSI they are likely to be overinflated. That said over inflation should help for fuel consumption, not hurt it.

[Lex_utor]

4 minutes ago, H3XME said:

Are they some Chinese tyres? Regardless.. They tyre bill fine. I drift on 65psi which is obviously more than what tyre states and it's fine. Either way, running tyre pressure at 40 and 45is fine. I do. But I have camber and stretched tyres. I need to run higher pressure tbh.

They are Toyo tyres.

[H3XME]

2 minutes ago, Lex_utor said:

They are Toyo tyres.

Hmm..I'll Check mine tomorrow. I use Toyo Proxes TR1

[Lex_utor]

3 minutes ago, H3XME said:

Hmm..I'll Check mine tomorrow. I use Toyo Proxes TR1

Mine are Proxes Sport if I'm not wrong. Yours are 19"?

[H3XME]

Just now, Lex_utor said:

Mine are Proxes Sport if I'm not wrong. Yours are 19"?

18

[Linas.P]

8 minutes ago, Lex_utor said:

They are Toyo tyres.

So what pressures do you actually use? and what exact size of wheels and tyres do you have?

[Lex_utor]

10 minutes ago, Linas.P said:

Just to clarify - so what pressure were you using? Because I am certain IS250 does not have pressures for 19" on door jam as such wheels were not fitted to IS250. IS-F has different pressures, because it has 235/265 tyres, so that would not be suitable for you unless you have 235/265s on 8.5/9.5J wheels. In general I would expect larger wheels would require lower pressures, if memory serves RC200t with 235/265 wheels required 22-24PSI, compared to 30-36PSI on 18". 

Under inflation could hurt fuel consumption massively - like 20-30% depending on how badly underinflated are the tyres. But looking at your tyres they don't look underinflated, they look like they are wearing on the edges which is common on IS250 and other Lexus cars... and assuming you put 30PSI they are likely to be overinflated. That said over inflation should help for fuel consumption, not hurt it.

I put 2.5 front 2.6 rear normally. I think that's what's on the door jam.

 

I just checked and in psi ISF seems to be 36-40. So not very different 

Sizes are 225/35 and 255/35

[Linas.P]

Yeah, 2.5-2.6 are about right, you could probably go higher than that depending on how tyres wear. They are definitely not under-inflated. That said Toyo Proxes are not exactly fuel efficient tyres. If I am not mistaken they are like D-E for fuel efficiency.

[H3XME]

5 minutes ago, Linas.P said:

Yeah, 2.5-2.6 are about right, you could probably go higher than that depending on how tyres wear. They are definitely not under-inflated. That said Toyo Proxes are not exactly fuel efficient tyres. If I am not mistaken they are like D-E for fuel efficiency.

Yeah Toyos aren't the best for economy but tend to have good dry or grip rating and the prices is very good. I need to change my front tyres (again, do it once a year) and I'm actually thinking of getting these https://tirestreets.co.uk/products/accelera-651-sport?variant=31649671872597

[Linas.P]

1 minute ago, H3XME said:

Yeah Toyos aren't the best for economy but tend to have good dry or grip rating and the prices is very good. I need to change my front tyres (again, do it once a year) and I'm actually thinking of getting these https://tirestreets.co.uk/products/accelera-651-sport?variant=31649671872597

Maybe don't... 🙂

If I found such tyre on my car I would replace it as priority, even if it is brand new. Just not worth having such tyres and the risk associated. I think one of 4 tyres on my IS250 is Accelera 😄 but as soon as car get's MOT, the next step is to refurbish the wheels and these tyres will go to the bin I don't care that they are like 6mm.

I mean sure if you have set of wheels you are using for drifting practice, then why not, they going to be trashed anyway. But in that case I would just go with Toyo's as they would be more predictable... and generally it is not good to use different tyres between practice and race, unless you don't do timed and it is just for fun anyway.  

[H3XME]

2 minutes ago, Linas.P said:

Maybe don't... 🙂

If I found such tyre on my car I would replace it as priority, even if it is brand new. Just not worth having such tyres and the risk associated. I think one of 4 tyres on my IS250 is Accelera 😄 but as soon as car get's MOT, the next step is to refurbish the wheels and these tyres will go to the bin I don't care that they are like 6mm.

I mean sure if you have set of wheels you are using for drifting practice, then why not, they going to be trashed anyway. But in that case I would just go with Toyo's as they would be more predictable... and generally it is not good to use different tyres between practice and race, unless you don't do timed and it is just for fun anyway.  

Well I heard good things about them on the forum. This compound is meant to be good. I only want good grip on the front and while the  proxes suffice, I don't mind trying something better 

[Linas.P]

There is never anything good about Accelera dichfinders. I remember hearing something positive about them, but I think it was from you LOL.

Again, I kind of understand cheap tyres for drifting, noise, fuel consumption and mileage isn't really relevant. Lack of lateral grip in the rear may even be desirable on car like IS250 which could sometimes struggle to overcome the tyres. But these tyres have no business being on the road - just outright dangerous and in my opinion should be outlawed. 

Funny enough Accelerra is typical suspect on tyre reviews used to show how horrible budget tyres are... and they never fail to disappoint. On dry they sort of "okey", but in wet they absolutely horrifying, unpredictable, uncontrollable and way below performance of even mid range. 

Here he specifically talks about rotalla, but in many videos accelera shows the same results... "okeyish" in dry - outright suicidal in wet. 

And here comes acelera:

 

[H3XME]

15 minutes ago, Linas.P said:

There is never anything good about Accelera dichfinders. I remember hearing something positive about them, but I think it was from you LOL.

Again, I kind of understand cheap tyres for drifting, noise, fuel consumption and mileage isn't really relevant. Lack of lateral grip in the rear may even be desirable on car like IS250 which could sometimes struggle to overcome the tyres. But these tyres have no business being on the road - just outright dangerous and in my opinion should be outlawed. 

Funny enough Accelerra is typical suspect on tyre reviews used to show how horrible budget tyres are... and they never fail to disappoint. On dry they sort of "okey", but in wet they absolutely horrifying, unpredictable, uncontrollable and way below performance of even mid range. 

Here he specifically talks about rotalla, but in many videos accelera shows the same results... "okeyish" in dry - outright suicidal in wet. 

And here comes acelera:

 

I get it but 651s aren't really a road spec tyre. You want good tyres on the front when drifting. I'm gonna try them anyway and report back.

[Linas.P]

That is what I said - "fine" for track, don't use them on the road. And even then if you need grip on front, they not great... they probably would be more suitable to set on fire in the rear.

[Las Palmas]

9 hours ago, Mr Vlad said:

Out of Interest what is the difference in rolling circumference between a 17" wheel shod with its correct tyre versus a 19" wheel shod with its correct tyre? 

215-45x17 17 215 45 625,3 1908,915215 1964,437886 523,8577346 0,078475336 7,847533632 205-35x19 19 205 35 626,1 1911,357454 1966,95116 523,1883748 0,001279386 0,127938589    I we should have 19" on the CT instead of 17" it would need 205/35/19 instead of 215/45/17. With 215/45/17 you need 523.86 revolutions to get you 1km With 205/35/19 only 523.19 to drive same distance.

[Lex_utor]

2 hours ago, Linas.P said:

Yeah, 2.5-2.6 are about right, you could probably go higher than that depending on how tyres wear. They are definitely not under-inflated. That said Toyo Proxes are not exactly fuel efficient tyres. If I am not mistaken they are like D-E for fuel efficiency.

They came with the car. I never had Toyos before. I normally used Michelin. Had Pirellis too. But I heard Toyos were good. 

 

But so you think 2.5 front and 2.6 rear are ok for the 19"?

[Lex_utor]

2 hours ago, H3XME said:

Yeah Toyos aren't the best for economy but tend to have good dry or grip rating and the prices is very good.

I like them. The car grips really well. No complains on the rain either.

But I can't say if it's the tyres or the car is just good, as the Toyos came with it and I never drove it on another set of summer tyres. They still have a lot of life left, but when time to change comes around, I will probably go Michelin. 

[Linas.P]

1 hour ago, Lex_utor said:

They came with the car. I never had Toyos before. I normally used Michelin. Had Pirellis too. But I heard Toyos were good. 

 

But so you think 2.5 front and 2.6 rear are ok for the 19"?

Yes should be fine. Toyos are okey for the price, they are typical midrange tyre. Maybe little noisy for my liking and not as fuel efficient as premium tyre, probably does not have same thread life either. Michelins are good, but overpriced. I probably would go with Goodyear Asymmetric 6 or Continental Premium Contact 6  if I were to buy premium tyre, depending what comes cheaper.

[Lex_utor]

On 7/27/2022 at 12:39 AM, Linas.P said:

Yes should be fine. Toyos are okey for the price, they are typical midrange tyre. Maybe little noisy for my liking and not as fuel efficient as premium tyre, probably does not have same thread life either. Michelins are good, but overpriced. I probably would go with Goodyear Asymmetric 6 or Continental Premium Contact 6  if I were to buy premium tyre, depending what comes cheaper.

Interesting that you find them noisy. On a Lexus? My car is so quiet that I wish I could hear a little more sometimes. Anything :) And I have sports exhausts. Unless I step hard on it, the car is so quiet. Even my wife comments on that. So I don't find the Toyos noisy at all. 

[H3XME]

Update: Had the Accelera 651 Sport fitted a couple of weeks ago. I have them on the front as the cords were showing on the old tyres (camber wear). I don't care what the reviews of other Accelerate tyres say, but these 651 Sport with 200 tread wear are fu*king amazing. Day & Night difference compared to the similarly priced Toyo Proxes TR1 I've been using. Incredibly grippy in dry and surprisingly good in wet too. I don't know what they're like in terms of aquaplaning on a REALLY wet motorway, but wet roads are just fine. Better than TR1 and those are to be "Wet" tyres. I'm chuffed with this purchase. The front just sticks. I tried to got at turns in a way to provoke some understeer which I could have with the old tyres but nothing happened, the car wouldn't understeer at all. I went for them because quite a few people on the GT86 group use them on the track & all round and the feedback is very good. Better than Advan AD08R. Accelerate Track tyres are completely different to their road tyres - those are awful. I'd recommend them if you want good grip, but they are track tyres, softer and therefore won't last as long as your regular road tyre which is fine with me because I change tyres every year due to camber wear anyway.

 Photo - I do have to say that they come out really stretchy. I lost some ground clearance, despite my old tyres being the same size (225/40 on 9.5" rims). You "should" really be running 255/265 on this width rim if you hate the stretched look, but anything over 225/235s is a complete overkill on IS250.. 

[Mr Vlad]

Mmmmmm they definitely look like a track tyre. Is there a 'not for road use' on the tyre wall? These tyres look like they should have. They definitely look grippy.

[H3XME]

4 minutes ago, Mr Vlad said:

Mmmmmm they definitely look like a track tyre. Is there a 'not for road use' on the tyre wall? These tyres look like they should have. They definitely look grippy.

No, they are road legal, just like Toyo R888 and Nankang NS-2R

[J Henderson]

Filled up last Friday and took this pic on Friday just past after a week of commuting.

Definitely drove slower than normal for this to happen. eg: 60Mph on motorways instead of 70-80.

[H3XME]

13 hours ago, J Henderson said:

Filled up last Friday and took this pic on Friday just past after a week of commuting.

Definitely drove slower than normal for this to happen. eg: 60Mph on motorways instead of 70-80.

I've been saying for a long time that these cars are not bad on fuel if you try.. if you try it's possible to get good mpgs.. with some cars you just can't get anything decent no matter how much you try and on the flipside, in a lot of small engine modern cars you'll get decent Mpgs without even trying..

Went to Guildford on Thursday last week to pick up mrs' new car, FK7 Civic Sport (1.5l 4cyl turbo petrol with 200hp).. I reset the mpgs before taking it out on a test drive on the nearby country lanes where I properly tested the power delivery etc 😄, went back to finish the paperwork and went back home to north west Birmingham. Motorway down by London wasn't great as you can imagine, even at 10:30AM. 60mph - 50 - 40 - 30 and some standstill traffic and by the time we joined the M40 it was smooth sailing at 72mph on the adaptive cruise control. Got home with 53mpg AVG for the day. If I drove the Lexus like I did the civic that day, I'd get home with probably 38.. I don't think I'd break 40s with the amount of slowing down and speeding up. and around town that civic still gets around 40 and it's a nippy car. It'd definitely give the lexus run for the money it being only 1300kg with almost 200hp. I feel like the mpgs could be better if I was able to turn off Adaptive cruise control as the car was slowing down unnecessarily too much even on the mildest setting. In my Lexus I'd just change the lane if I was approaching a car while on cruise control.. the Civic would start slowing down before I even got to the point where I'd normally be changing lanes.