Skinnyman

I can’t remember exactly what load rating the Unis are - I’ll check later when I go out - but I’m pretty sure they were at least as good as the ratings specified by Lexus. Given that the car isn’t that heavy and is unlikely ever to go over 120mph, they do seem to be over-specified anyway. The marketing bods probably insisted on “performance” spec tyres when touring or all season would be plenty good enough - and probably more useful to most owners!

In the end I went for Uniroyal Rainsport 5 in the standard sizes. So far I’ve been delighted with them. They’re not an all-season tyre but they were perfectly good yesterday in the snow and slush we had. I might be concerned trying to get through a 2-foot snowdrift with them and I don’t know how they’ll perform in very icy conditions but so far they’ve been excellent. Wet weather grip is stunning and ride comfort superb. Hope that helps!

After much dithering and discovering that the Dunlop Sport Maxx RT aren’t available any more (to my local fitter at any rate), I finally went for Uniroyal Rainsport 5. I know these aren’t to everyone’s taste but, for me, they’re excellent, I’m really pleased with them. Comfort is a massive priority for me and the Unis are so much more compliant than the old RE050a that I took off. Grip is excellent - maybe not good enough for a track day but plenty good enough for a spirited run down the B6407 on a warm summer evening. I’m also hoping that they’ll live up to their name and be decent in the rain and, going by the reviews online, be reasonable (for summer tyres) in cold temperatures. There aren’t many tyres available in the OE sizes and for £800 for the set, fitted, these worked out much better value than the £1200 I would have had to pay for Michelin PS4S’s or the £1000+ that Bridgestone RE050a’s would have cost. We all have different priorities when it comes to tyre choice - the Uniroyals match mine really well.

Given the abysmal state of the roads these days, given that everyone with a Dashcam is being encouraged to send in evidence of anyone enjoying themselves on the public road and given the number of speed cameras there are everywhere, I’ll take comfort over speed these days. I sold my 911 because there was nowhere I could use it to anything like its potential without risking a jail sentence. I sold my Lotus Elise because I like my fillings in my teeth, not in my lap. I do regret selling my 350z - that was a great GT car - and I sold my F Type because it was just so shouty and look-at-me loud and I hardly used it so it was really just an expensive weekend toy. I love the refinement of the RC. I love that I can use it every single day and that it’s the only car I need in my garage. I love that I can spend 8 or 9 hours driving on A and B roads and not need a chiropractor when I get out. I love that, when I really want to, I can stick it in Sport+ and “make progress” but get the sensation of speed at sensible speeds that won’t see me in jail or upside down in a ditch. The other cars I listed above were all great “sports cars” - great when going fast on an empty road in ideal weather, not so great the rest of the time. The RC works for me at all speeds on all roads. OK, the exhaust note is nothing to write home about but when you’ve spent 6 hours in an Elise with the engine roaring by your left ear, you really appreciate the finesse of the RC. To the OP - if you want a car you can remap and tune and stick a loud exhaust on, you’re not ready for an RC yet 😁

I know that some vehicles (Jag XJ for example) have battery monitoring software that doesn’t like it if you connect direct to the battery terminals, bypassing the software. For that reason, they insist you connect to specific connection points rather than directly to the battery. I don’t know if your friend’s Jetta had a similar system which caused it to fritz but the RC is much more straightforward. What Herbie says makes perfect sense and I don’t think the OP has anything to worry about. On a different but related note. I’ve been paranoid about battery life since a BMW X5 let me down in Manchester some years ago so I plug mine into a battery conditioner overnight when I put it in the garage.

There are quite a few GY Eagle F1. Are yours the Supersport, Asymmetric 2, 3, 5 or 6? And did you get run flats?

Interesting…. How does the ride comfort compare to the Bridgestones? If they’re a decent, compliant ride over bumps I might consider them when I change in a few months time.

I think you’ve summarised the issue nicely - there’s a very limited choice of tyres in the rear size. I could change tyre size but that raises all the issues of whether insurance companies need to know, etc. I’d happily fit Primacy or Conti Premium but if they’re not made in the RC size, they’re not an option. I’ll take a look at the Uniroyal and see how they compare to the Bridgestones - if they’re an improvement then I’m happy to give them a go. If not, at least the PS5 are now an option.

I hear what you’re saying and you’re right, PS5 are overkill for the RC300. But…. Leaving aside the “at the limit” performance tests, in every comparative test I’ve seen, including (for me) the important ones of Comfort, Noise, Aquaplaning, and Wet Braking, the PS5 wallops the Bridgestone. I had PS4 on the F-Type and they were a massive improvement in comfort over the OE Pirellis so there’s a good chance the 5’s will be as, if not more, comfortable than the Bridgestones. There’s a difference in price but it’s not huge and one I’m prepared to pay for tyres that stop me more quickly and are safer in the wet. I’ll give them a go when it’s time and if they’re not a huge improvement I’ll go back to Bridgestone on the next swap.

The PS5 is available in the right sizes for the RC300h - I think this is a new size as they weren’t available a few weeks ago when I last checked. I’m tempted to try a set when the current Bridgestones give up the ghost.

I don’t mind Fifth Gear these days. They’ve stopped trying to copy Top Gear and gone back to being a straightforward motoring programme. But I agree - putting a 2019 car up against 3 brand new ones seems unfair unless they wanted - and were clear that they wanted - to show how much progress has been made in just three and a bit years.

Isn’t the RC limited to 118mph? The 300h anyway I’m sure I read that somewhere. In which case, T-rated tyres or better should be all that’s needed? I know that’s not what Lexus specify, but it’s all that the car needs of it can only do 118mph

My guess is that the RCF needs extra bracing across the rear axle because of the extra power….?

After spending some time with a wheel size calculator, it seems that 255/35 R19 would be a good alternative for the rears. It seems a better size for the 9” rim, it’s 1.06% difference in speedo rating (and would over-read which is safer from a speed camera perspective). The GY Assym 6s are available in that size and in the front size. Changing to 255s would also open up a range of all-season tyres such as the Goodyear Vector4. I guess the only question would be whether a different tyre size would have an impact on the insurance and on the warranty. That said, if the tyres are a road-legal fit for the car and they match the speed rating, I don’t see that they could be a problem, especially if one advises the insurer. I guess my question is now - has anyone else changed tyre sizes to take advantage of the wider choice of rubber?

I’ve spent a fair amount of time recently looking at the tyres available in the staggered 19” sizes and the choice seems quite limited. Where rears are available, they don't do the front size and vice versa. I’ve looked at the latest Premium tyres; Michelin PS5s, Conti SC7s or Goodyear F1 Assym 6s but I can’t find anywhere that does full sets of any of them in the RCs sizes. Having said that, I’m not sure that I’d exploit the full potential of Ultra High Performance summer tyres so maybe something a bit more GT-focused would be better. My priorities are wet-weather braking and handling and comfort over out and out dry grip. I suppose i could change the rear tyres to a different size. Maybe 255/35 or even 245/40. What’s everyone using? The current Bridgestones are okay but i’m open to suggestions if there’s anything that meets my criteria better.